Vintage Oldsmobiles Curved Dash, Limited Touring, Models 40, 53, 66; Series 60, 70, 90

1946 1947 and 1948 How many own them?

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Old June 14th, 2012, 09:02 AM
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47 Coupe, Its a dandy, and original too. Can't ask for much more than that. I'd be happy if my 47 turned out that nice.
Jerry
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Old June 14th, 2012, 09:18 AM
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Originally Posted by MontanaMike
Bill,
I have two cars, both straight 8's. One I will rebuild for sure - but the other is questionable and I won't make that decision until after I rebuild the first. Affordability is a big question. So is reliability So I can see where a nice little Old's 215, 307 or 350 could come in play. Then there is the front spring question, and brakes, - and - and - and - and -
You see what I mean. Engine swaps make for interesting nightmares too.
MT Mike, One of the things I like about this site that keeps me coming back is the appreciation of different builds on our Oldsmobiles. Rodders don't put down restorers and vice versa. I can see the same spirit prevails among our little sub-group of 46-48 folks.

re. engine exchanges, those old cast iron straight 8s and 6s probably weigh about the same or more, particularly with the old hydramatics, than the newer V8s with aluminum bodied transmissions. There might not be any need to change suspensions.
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Old June 14th, 2012, 12:28 PM
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Jerry,
You are right about the Resto folks getting along with the Rodders. I probably will end up being both.
I read somewhere awhile back that the straight 8 / Hydramatic combo weighs about 300 lbs more than a 350 c.i. / Turbo combo. I don't know if that is true or not, but different spring load and height combinations can be bought at Kanter and other places.
The point is, and the one I was trying so poorly to make - no matter which way you go I think the cost is probably comparable if you figure all the other stuff a hotrodder has to consider, from a 12 volt conversion, disk brakes & steering (either Fat Man or the local junk yard Mustand II) , radiator core, springs, body fabrication, to electric windshield wipers and on and on. Some of those things might also need to be done on a restoration, but a $5000.00 rebuild for a straight 8 might be the deal of the century. It is something that I will be pondering for a long time.
It would be very nice (and also very helpful), if some of the Rod builders out there who have the experience (and recent cost records on their conversions), to share some cost estimates for parts needed to rod a 46-48 Olds. I know that I will be restoring one of my cars to as near original as I can, but the other is up in the air.
OH! and after I get done with the chassis and body metal, I get to tackle the wood.

Keep Building
Mike

Last edited by MontanaMike; June 14th, 2012 at 12:37 PM.
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Old June 14th, 2012, 05:18 PM
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I had a machine shop mechanic tell me that I could figure $650 a hole for the machine and assembly, that is if he could obtain parts at a reasonable price.That seems about right from from a mid fifties car, don't know about a forties era motor.....Tedd
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Old June 14th, 2012, 08:02 PM
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47 Coupe to Jerry; I feel after you get through it will be nicer than mine. Keep up the Great work. Looking forward to seeing the progression.
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Old June 15th, 2012, 07:56 AM
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I like cars that run! By that I mean freeway/highway speeds and when the traffic stops, I want to stop in a safe straight line.
It was my original intent to keep my '49 Old's basicly stock, drum brakes, lever shocks and the 303 V8 w/hydro.
I had a '50 Old's 88 in '54-55, that car would run at 100 + mph on the open roads of Nevada hour after hour.
Of course I was 24/25 and invincible, also the traffic was light, a motorists greatest fear was Jack Rabbits and the open range cows.
I believe that I have made mention in my '49 Old's rebuild thread that my thinking changed when I found out the cost to rebuild a 303 and a hydro, plus the fact that the 303 + hydro unit weights over 300 lbs. more than a late model 350 Old's 350 trans.
My suspension thinking got changed when it was explained to me by Brent @ Fat Man, the positive side of upgrading the suspension to late model components..
The theory behind modern suspension is the elimination of front end dive under heavy braking. Front end dive causes weight transfer from the rear axle to the front end, the loss of rear axle weight causes the rear brakes to lockup, thereby causing an uncontrolled skid...
I believe we have all experienced the rear end of a car wanting to come around and meet the front end at one time or another.
If I was just going to drive my Old's down to the local Friday night cruise or maybe a little romp out on the highway to blow the cobb-webs out, I would not go to the trouble of modernizing the mechanical aspects of the car... I like to drive my old cars in the 'fast lane'.... Bill
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Old June 15th, 2012, 08:23 AM
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We should all do what pleases us and meets our needs. Why else be into such an expensive hobby. I appreciate all the old cars but over the years have toned down my builds from out-and-out hot rods to resto-rods. Who knows? One of these days if I find a nice survivor like 47 Coupe's car I might just leave it alone.

I was up at the new LeMay car museum in Tacoma, WA. Wed. with my coffee buddies and saw hundreds of restored cars from the teens through the 60s plus a few hot rods that are in the display. A nice 48 Olds coupe in original condition that caught my eye too. Other highlights, 12 Ferraris all in a row together. Well worth the admit price and not all that crowded when we were there. Photos including flash are allowed. You might want to bring an extra battery for your camera.
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Old June 19th, 2012, 07:44 AM
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I'm a newbie - just joined last night. I have a 48 Olds Club Coupe in restoration. When I retired a couple of years ago fishing & golf got old, so my kids decided I needed something else to do. I was an hot rodder years ago, and my son is heavily into it now. He is Heating/AC and one of his customers had a 48 Club Coupe in his garage gathering dust for 10 years - never moved or started. The owner had started building it, but health problems brought it to a halt. So on Fathers Day last year, as a complete surprise, my 3 kids bought it for me! It has a 383 stroker, 700 R4 tran, Mustang II frontend. The motor was froze-up from sitting, so we went to work and we're having a great time! I need certain parts (chrome pieces, etc.) and hope this forum can help.
My son and I bought another 48 Coupe last night that we were going to use for parts. Its not exactly like mine - has the slope back. After looking at it though, we've decided it is a builder for my son. I plan to use the bumpers and some other parts off of it, because he will want to completely customize it himself.
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Old June 19th, 2012, 10:46 AM
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Hey and Welcome, We are a growing sub-group of 46-48 owners. What kind of rear end and rear suspension does it have? Post some pics of the car on here. Not too difficult to do. When you are in the advanced message mode scroll further down the page under Additional Options and then Attach Files and then click Manage Attachments and it will lead you through putting up pics. There is a size limit so you might have to edit down the pic size on your computer photo program first.

Always fun to see what others are doing to their cars.
Jerry
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Old June 19th, 2012, 01:57 PM
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Originally Posted by Kustom King Danny
I'm a newbie - just joined last night. I have a 48 Olds Club Coupe in restoration. When I retired a couple of years ago fishing & golf got old, so my kids decided I needed something else to do. I was an hot rodder years ago, and my son is heavily into it now. He is Heating/AC and one of his customers had a 48 Club Coupe in his garage gathering dust for 10 years - never moved or started. The owner had started building it, but health problems brought it to a halt. So on Fathers Day last year, as a complete surprise, my 3 kids bought it for me! It has a 383 stroker, 700 R4 tran, Mustang II frontend. The motor was froze-up from sitting, so we went to work and we're having a great time! I need certain parts (chrome pieces, etc.) and hope this forum can help.
My son and I bought another 48 Coupe last night that we were going to use for parts. Its not exactly like mine - has the slope back. After looking at it though, we've decided it is a builder for my son. I plan to use the bumpers and some other parts off of it, because he will want to completely customize it himself.
Hi, From your description of the car it sounds like you have a pretty good start on building a nice resto-rod.
You stated that the engine in the car is a 383 stroker, I would surmise that you meant a SBC 383..
If the engine is stuck you might consider replacing it with an Old's 350, that way the power train would still be Oldsmobile.
Is your front end really a Mustang II unit? If it is, it could be a little light and to narrow for your car. An early GM Camaro is a good fit under the Oldsmobile's, however, most people don't mess with the junk yard donner parts anymore... By the time you buy the parts, then have to rebuild everything, buying a new Fat Man, TCI, etc., is more cost effective.
I clicked on your friend request... hope it went through.... Bill
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Old June 19th, 2012, 07:29 PM
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48 Chevy Club Coupe

Yes it is an SBC 383 Stroker. It has a Chevy 12 Bolt rearend - rest of the suspension not sure - we're working on it. Thanks for the input! Any and all suggestions welcomed.
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Old June 19th, 2012, 08:54 PM
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Thanks for adding the photos. Nice looking coupe.
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Old June 21st, 2012, 10:45 AM
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Originally Posted by 480ldsmobile
beautiful olds!!!! i saw pictures of your ride and thought it was awesome. PLEASE provide details on build specs.
As of right now all is some what stock/original I did convert to 12v though. Original inline 6 and hydramatic tranny. I did add airbags for the low look and did rechrome many parts.. The paint was redone last year same color scheme just a little lighter. Removed the cloth interior and went all vinyl including headliner ( off white ) the dash and window frames ( inside ) was all redone to look like woodgrain.
right now I had a stuck valve and removed the exhaust N head and was lucky to just have a slight build up of S/\!T was able to break free and clean all valves with Kroil. Now time to put back together. Anybody know of the correct color to paint block, head, exhaust...... Or a drawing on the firing order to the dist cap? I believe I marked it all right just need to double check.
As soon as I get this running again ( hopefully in a week or so ) I will post up some inside n outsie photos Here are few ever see an oil filter like this?
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Old June 21st, 2012, 01:23 PM
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re. Oil Filter. Similar oil filters used to be common on late 40s and early 50s cars. They mount independently and are not full-flow. Maybe 10-20% of the oil was diverted through the line and filter and back to the engine. I guess the theory was that eventually all of the oil would get filtered. I'm not sure from the amount thick, black gunk found in oil pans that all the oil was filtered in any satisfactory manner by these partial flow filters. They were a heck of a lot better than none though.

I don't know about other makes but Chevrolet had a full flow oil filter by the late 50's but it still mounted independently. I had a 1961 261 cid straight six that was this way. It was a pickup engine. Usually they were mounted to the intake and had fairly large hoses connecting engine to filter and back to engine. I don't know the exact year but it seems to me it was the early 60s when the oil filter boss was cast into blocks and filters screwed directly to the block with no exterior lines. My memory of all this goes back to working in service stations and doing hundreds of oil changes as a teenager. If you're under 60 years of age you are excused for not remembering all this ancient history : )
Jerry
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Old June 22nd, 2012, 07:09 AM
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If my memory is working correctly... I think that starting with the Old's 303 V8 in '49, the oil filters were all the full flow type with the oil canister mounted directly to the block.
The overhead valve '49 Cad's were most likely full flow also. The '55 Chevy 265 V8 was a full flow, canister mounted to the block, however, the inline engines did not go to full flow until the 230 CID engine came out in '63.
The early canister type filters that Old's, etc., used were a real problem. Being mounted low on the block it was very common for them to be poorly installed following an oil change.
I had a '50 Old's 88 in '55, I had it serviced, the lube man did not remove the old 'O' gasket from the canister, putting a new gasket over the old one. Upon picking up the car late in the afternoon my girl friend and I headed out of Vegas to Lake Mead for a night time beach party. Buy the time we got to Lake Mead the engine was rattling very badly, there was oil all over the engine because the filter had started leaking.
The engine was ruined with less than 30k on it... I traded the car in on a '53 Super 88....Bill
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Old June 29th, 2012, 03:39 PM
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I'm picking up a 48 Club Coupe next week after the 4th. The seller apparently inherited the car from a deceased friend and knows very little about it.
After looking at it the front end looks like a mid 80s Camaro steering, suspension, disc brakes, etc.
Early 80s Olds 307 motor and T350 trans.
Original 48 rear end with modified shock setup.
Camaro steering column.
Power steering & brakes.
Working AC !!
Older custom interior and trunk.
American Racing wheels.
Nice older paint job.
Runs and drives pretty good.
Whoever did the work did a very nice job putting everything together.

This will be an experience, I've been an A body guy for 30 years. But it looked like too good of a deal to pass up. I'm sure I'll get an education!

Marv
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Old June 29th, 2012, 04:46 PM
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Originally Posted by MnOlds
I'm picking up a 48 Club Coupe next week after the 4th. The seller apparently inherited the car from a deceased friend...
This will be an experience, I've been an A body guy for 30 years. But it looked like too good of a deal to pass up. I'm sure I'll get an education!
Marv
Hi Marv and congratulations on your new old Oldsmobile. It sounds like the hard work is mostly done. Keep an eye on this thread in this forum. A number of us with experience with modifying and some keeping them stock but all enjoying them.

There is a project Olds coupe of about the same vintage on Seattle CL for $7,500 and it looks like most of the work is done plus some expensive rechroming that's just waiting to go on after a new owner paints. If I didn't have my 47 convertible I'd really be tempted at that price.

Jerry
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Old June 29th, 2012, 08:55 PM
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Sounds like a great car, Marv! I've got a 48 Club Coupe - still lots of work to do on it, but really enjoying it. I like to hear when other folks make a good find.

My grandson and I just got back a few hours ago from picking up a 48 Club Sedan from a storage lot. It needs alot, but its a real good find. I'll post some pics when I can and would like to see pics of your Club Coupe.
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Old June 30th, 2012, 09:13 AM
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Hey Marv welcome to the group. Throw some pictures up when you get the chance.

I am installing rear disc brakes on the rear of my 48 as soon as it rolls again I am going to test fit the 455 and TKO trans they are fully assembled. Then when I am satisfied that the fitment is good. Its of to get sandblasted and primed for final body work. Been a long time coming to this point. Lots of stops and starts
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Old July 5th, 2012, 12:10 PM
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Thanks for the encouragement. I'll post a few pics after I get it cleaned up a little.
Right now I'm waiting for axle seals, pinion seal, rear brakes, etc. It's pretty greasy back there and the brakes needed rebuilding.
Other than that it's just a bunch of cosmetic stuff, I should be rolling some time next week if the part show up!
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Old July 5th, 2012, 12:42 PM
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Marv, Thanks for the post. I'm in forest Lake MN and have a 48 Dynamic. it's about 99% complete resto-rod. I have run across about 7 other guys around the Twin cities with curved dash Olds and you would be #9. Would be fun to put together a local curved dash olds get together. The MN Olds club has their car show Sunday July 29 at the Blacksmith Lounge in Hugo MN 7-3:00 if you get it ready. I haven't gone to the show but twice but since it is less than 2 mi from home i am considering it this yr. Welcome and Keep posting.
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Old July 8th, 2012, 05:38 PM
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Another late one!

Coming home yesterday from our usual Saturday breakfast, my 48 Olds Coupe, the Mona Lisa, started to miss quite a bit. So last night was another late one - My son and I finally called it a night at 4 am. We put a new MSD distributor and new Taylor plug wires on and got the carburetor set and she's finally purring like a kitten! Some fun 'eh kids!
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Old July 8th, 2012, 06:03 PM
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Originally Posted by Kustom King Danny
Coming home yesterday from our usual Saturday breakfast, my 48 Olds Coupe, the Mona Lisa, started to miss quite a bit. So last night was another late one - My son and I finally called it a night at 4 am. We put a new MSD distributor and new Taylor plug wires on and got the carburetor set and she's finally purring like a kitten! Some fun 'eh kids!
Is there a 4 on the a.m. side of the clock
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Old July 10th, 2012, 07:59 AM
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1947 238 inline 6 head torque sequence

I know its about 60-70 lbs of torque to replace the head but is there any real sequeance that I should follow?? Took some time but all my gaskets arrived now need to get car ready for this weekend Doing an escort for a freinds daughters sweet 16
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Old July 10th, 2012, 09:30 AM
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Try this for 8 cyl. same site has 6 cyl also: http://www.secondchancegarage.com/public/539.cfm I didn't see a sequence chart but generally work from the center out toward ea. end alternately. The idea is to bring the head down on the block evenly and not torque one end first. I was also taught to go to about 30 lb torque the first sequence and then go back using the same pattern and tighten to specs. Run it and let it cool and then retorque to specs. Some folks also retorque after putting on some miles

Jerry

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Old July 16th, 2012, 04:20 AM
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Gas Mileage Question

The antique plates finally came and I'm now driving my '47 quite a bit.

I even broke down and installed points/plugs/rotor and cleaned out the carb before driving it. It starts and runs just great!

Since I've had it, it's always been really good mechanically, aside from a few drips from the transmission. The front end is tight and the old knee-action front shocks work adequately and don't leak.

But......

When it was last driven in Kentucky, gas was quite a bit cheaper so I didn't really pay much attention to how much it was using.

Lately, I've been monitoring it more closely and the results are pretty grim. So far, it's averaging low to mid-11s. This is the stock 6-cylinder flathead six I'm talking about, not some cammed-up 455!

Here's what makes it so sad, I have a '67 Camaro with an '06 LS7, 4L80E transmission with a 245mm, 3400 converter and a 3.90 rear end. It's local (non-trip) mileage is ~14.2 mpg. It weighs 3320 lbs where the Olds weighs in at 3618, so there's not a huge weight difference.

I'm certain that technology is at play here but damn, it's only 217 cubic inches and is about as mild as it can be (0-60 times are measured with an hourglass).

Does anyone else have similar results?

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Old July 16th, 2012, 10:14 AM
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11MPG 47 Olds

Its sort of hard to feel a lot of sympathy for your mileage issues when you are 'forced' to put the Olds in the garage and drive the LS7 Camaro in order to get what even begins to approach decent mileage.

Our family had a 50 Pontiac way back when and I remember Dad grousing about getting a lousy 14 mpg with the mighty flat head 8 on trips. Of course we were paying $0.26/gal for petrol so it didn't hurt too much.

I think you are right that you are fighting old tech vs. new tech. Right after WWII there was so much pent up demand for new cars that manufacturers could sell anything they threw together so no pressure was on them to produce better technology. Only Buick and Chevrolet had overhead valve engines. Even high end cars as Chrysler, Packard and Cadillac stuck with flat head engines until just around 1950.

Some things you didn't mention in prepping the old Olds: new spark plug wires, timing and actually rebuilding the carb instead of just cleaning it out. You could probably pick up a mile or two per gallon by changing to radial tires and running higher than recommended pressures. Adjusting the valves could help as well. Even under the best circumstances it is probably not realistic to expect much better than 14-15 mpg particularly if you're running a hydramatic trans in the Olds.
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Old July 19th, 2012, 09:01 AM
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Originally Posted by 1948-78
I have run across about 7 other guys around the Twin cities with curved dash Olds and you would be #9. Would be fun to put together a local curved dash olds get together.
That would be interesting to see. You don't see too many Curved Dash Oldsmobiles around as they were only made from 1901 to 1907.
Doug.
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Old July 22nd, 2012, 07:35 AM
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hello, i am new to the site. live in st cloud mn. i have a 46 series 76 club sedan 2 door, starting process of mod restore, using a 71 455 and th400, already had a mustang 2 front end and rear end when i got it.
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Old July 30th, 2012, 06:06 PM
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I finally found the time to check everything out and make sure it's roadworthy. I wasn't able to take it for a good test drive before I bought it because a frost plug was leaking. Turns out it runs and drives very nice, it's a 84 307 with a T350 trans, original 48 rear end. The rear axle seals and pinion seal were all leaking, probably for years, what a mess. That took a long time to clean up, replace seals, brakes, etc.
The body is very straight with no evidence of any rust problems. New rubber/seals, etc all around.
The Camaro front end parts all look like new.
AC, tilt and cruise all work.
It's looks pretty darn good after cleaning it up!

Marv

****Anyone know where I can look up the gear ratio for an original 48 rear end?
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Old July 30th, 2012, 11:33 PM
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You move pretty fast on getting it in shape. It was less than a month ago you posted that you had that rear end and other stuff to do. Sure looks good now after clean up and ought to be a very dependable ride for road trips. Congratulations and help us keep this thread going by posting whatever you are doing on or with the Olds.
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Old July 30th, 2012, 11:41 PM
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48 Olds Coupe

MnOlds, my info says rear end ratio for std. trans 48 in your model is 4.3:1 and for hydramatic it is 3.64:1 so you will need to know whether your coupe was automatic or std. trans when manufactured. Or, jack it up, mark the driveshaft with a line and turn a rear wheel exactly one revolution and see how many driveshaft revolutions there are for a complete tire rotation. That should get you close. Less than 4 would be the 3.64 and over 4 turns of the driveshaft would be the 4.3 ratio

Last edited by 47 Convertible; July 30th, 2012 at 11:46 PM. Reason: add information
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Old July 31st, 2012, 08:12 AM
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Regardless of what ratio your differential is, 4.3 or 3.64, either of these ratios are way to low for a modern V8 with an automatic trans. That is unless you want a 1/4 mile drag car in lieu of a nice highway cruiser.
Your best choice for a replacement rear end would be a GM 10 bolt out of an early Camaro.. The Camaro rear ends are 54-1/4" backing plate to backing plate, 61" hub to hub OD..
Most of the early Camaro's had a gear ratio in the 3.23 range, some will be found in the high 2.'s... Do not get a rear end out of a Olds/Pontiac.. They are whats referred to as BPO's and generally speaking are not re-gearable. The GM Corp rear end which Chevy used will have any of three ring gears, 8.25, 8.5 or 8.3/4... Opt for the 8.5 or 8.3/4... The 8.25 ring gears will be in the low performance cars... 6 cyln, small V8.
The one problem with the Chevy rear ends is the bolt pattern... It will be 5 on 4-3/4 where-as the Olds is 5 on 5... Only Buick Olds and Chevy half tons used the 5 on 5" bolt pattern..
Been there done that on my '49 Olds... I opted to keep my original type of '49 Olds rear end because of the rear suspension. Did re-gear it to 3.24. I had FatMan drill my front rotors with the 5 on 5 bolt pattern so I could use my stock wheel centers, this will let me use the stock dog dish hub caps.
If your car started out life a six cyln it will most likely have the small 1-34" brakes on the rear.. The 98's had bigger brakes as did the 88's starting in '49.. I put the 98 brakes, 2-1/4" on the rear of my '49...
As you can see I have already been down this trail with my car.. Do your home work before you jump into the "pool"....Bill
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Old July 31st, 2012, 08:33 AM
  #114  
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Cool

Originally Posted by Bulldowg
hello, i am new to the site. live in st cloud mn. i have a 46 series 76 club sedan 2 door, starting process of mod restore, using a 71 455 and th400, already had a mustang 2 front end and rear end when i got it.
It could be that you should rethink the application of a 455 in a car with a Mustang front/rear end.. If you have in fact Mustang suspension, it is far to light for a car as heavy as the '46 Olds, especially with a 455 in it.
A small block Olds 350 with a 350 trans would be a better choice... You could pick up this combo from any 4dr '77-79 Olds.. It would not be a hot rod, however, it would run much better that the original 6 cyln ever thought of.
Another factor to consider is the size of the 455's, they are wider and taller than a 350, therefore they are very difficult to mount in a 1940/50's chassis.
I was cautioned about such an application when I was planning the modifications to my '49 Olds. Of course everyone wants the bragging rights of having a 455 in their car.. I am using a '76 Olds 403 in my '49.. Bill
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Old July 31st, 2012, 11:36 AM
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I think swapping the T350 trans for a 200r4 or 700r4 would be a better solution than trying to put a modern rear end in a 65 year old car. The 3.64 would be tolerable on the highway, the 4.30 not so much.

My 64 has a small block Olds, 200r4, and a 4.11 rear end. It's fine cruising at 70 mph all day long.

I do agree with the other post that a 455 on a Mustang front end may not work out well. The 48 front ends are low to begin with, adding all that weight could be a problem.

Just my humble opinions.


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Old July 31st, 2012, 02:14 PM
  #116  
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Smile engine and front end suspension considerations 48 Olds

[QUOTE=MnOlds;435173]
I think swapping the T350 trans for a 200r4 or 700r4 would be a better solution than trying to put a modern rear end in a 65 year old car. The 3.64 would be tolerable on the highway, the 4.30 not so much.

I agree. OD automatics with the .7 overdrive change a 3.63 rear end to an equivalent 2.54:1 ratio which should allow cruising at 70 mph at somewhere around 2100 to 2200 rpm with about a 27 inch total height tire (this is all from memory and I might be off a little bit). The 4.30 ratio is reduced to 3:1 with a .7 geared overdrive. Still OK in my book for highway cruising. The 2.7 - 2.5 factory rear end ratios were made for the 3 speed transmissions like the TH350 that didn't have overdrive.

It is work to adapt a non-stock rear or transmission so I'd call the jobs roughly equal but the great advantage of the OD transmission is you can have that snappier lower ratio axle for around town and stoplight-to-stoplight fun and still have a road cruiser with the .7 overdrive.


I do agree with the other post that a 455 on a Mustang front end may not work out well. The 48 front ends are low to begin with, adding all that weight could be a problem.

Not to be contrarian on the front end suspension issue but remember the basic MII suspension was used by Ford on cars as large as the Lincoln Versailles which weighed around 3,900 lb. Your 48 Olds Coupe probably weighs around 3,800 lb if the sources I looked at were correct. I am going to guess that weight distribution was about the same for the Lincoln Versailles as for the 48 Olds-- maybe 55 to 60% on front. The Mustang II suspension is more rugged than it is generally given credit for. Don't replace it until you try it. You will probably need heavier springs than stock MII but that is not a big issue as a reputable spring builder can give you a recommendation if you can provide some basic information on your car like weight and intended use.


Final bit of data: The 455 Olds is shown as 620 lb. and the SBO at 560 lb. 60 lb difference. Not enough in my book to rule out the 455 with it's glorious low rpm torque. There are a number of us who have or are in the process of, putting 455s in our 46-48 Oldsmobiles. I have test fit and built mounts for a 455 with 700R4 in my 47 Convertible. Everybody has their own ideas about what a tight fit is but I wouldn't call my 455 a tight fit. Close yes but not tight. I didn't have to move the firewall or radiator location and can reach down around the sides to do wrenching.
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Old July 31st, 2012, 08:22 PM
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gear ratios

I made a mistake in my earlier posting to this thread... The ratio of the rear end under my '49 Olds is 3.42... I am using P215R65-15 tires which are 26.5".
I am using a 200R4 trans that has been bullet proofed to withstand over 500 HP.. One of the disadvantages of the TH400/700R4 transmissions is there size... It can be a tight fit in the Olds X member frame... The 200R4 trans is pretty much the same size as the TH400.
I considered changing the rear end to a early Camaro 10 bolt w/8-3/4" ring gear. The big reason was to gain bigger brakes on the rear.. My front brakes are 12" disk. It was felt that the original 2" rear brakes were not up to the task of stopping the car safely at 70+ MPH... Changing to the 98's 2-1/4 rear brakes, the 2" & 2-1/4" brakes use the same drum. I only had to buy the 98 brakes and a install kit for same...
It did not look to me like the differential swap, old to new was that big of a deal.. Carefully remove the hardware from the stock Olds rear end.. Remove the hardware from the new rear end and install the Olds hardware onto the new rear end.. About a four hour job... Bill
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Old August 1st, 2012, 12:57 AM
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[QUOTE
It did not look to me like the differential swap, old to new was that big of a deal.. Carefully remove the hardware from the stock Olds rear end.. Remove the hardware from the new rear end and install the Olds hardware onto the new rear end.. About a four hour job... Bill[/QUOTE]

Some work faster than others and I admit I'm pretty slow now that I'm into my retirement years. I'm sort of embarrassed to tell you it took at least ten hours to take out the old, set the two rear ends side by side, do the measuring, built templates, double check, fabricate brackets and weld to axle housings and reassemble and reinstall. But heck its a hobby and if I wasn't in my shop doing something like this I'd be in a bar which is not much fun at my age.

A couple of pics of my 8.25 BOP rear out of a 67 GTO should be on this reply. I like the 40s Olds rear suspensions and believe your idea of keeping most of it and just swapping the rear end is a good one. I did have it rebuilt and 3.54 gears plus a posi carrier put in. I like the axle retention feature of the BOP better than a Chevy rear end and the two caps on either side of the carrier look heavy duty enough to have come from a truck. I gotta think Pontiac engineers knew what they were doing putting that rear end on a GTO
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Old August 1st, 2012, 08:56 AM
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rear shocks

I noted from '47 conv' pix that he converted the rear shocks to tube type.
I considered changing my shocks from the original lever style to tube type. I was concerned about altering the geometry of the rear suspension.. I wanted to lower the rear end about 2" to match the 2" drop FatMan engineered into the front clip. After checking around I decided to purchase new rear springs. The springs I purchased are re-engineered to allow for the 2" drop. I sent my lever shocks out to a company in Santa Anna, CA to have them rebuilt with HD valving and to re-position "re-clock" the arms to allow for their new angle created by the 2" drop.
In the old days, when I was younger and thought I knew everything, I would have "torched" the springs to drop the car... That is the difference between "Old School" and more modern safety first thinking....Bill
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Old August 1st, 2012, 11:54 AM
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rear suspension observations

[QUOTE=blucar; ....The springs I purchased are re-engineered to allow for the 2" drop...
In the old days, when I was younger and thought I knew everything, I would have "torched" the springs to drop the car... That is the difference between "Old School" and more modern safety first thinking....Bill[/QUOTE]

1. Can you provide a contact for those re-engineered rear springs. I'd be interested. Thanks.

2. I think we all torched springs when we were younger, poorer and didn't know any better. Then we cruised around looking like bobble-heads because the front end only had 2 inches of travel.
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