1968CutlassSupreme

Hello CO friends!

It would be nice to be able to just pull up a magic site that would tell you exactly what you needed without having to try to explain what you are trying to do, wouldn't it? I am very new (a couple months here) and I am reading and receiving differing views on what is good or bad or what to do, etc...

I have a rocket 350 that seems to be in pretty good shape (no smoke or rattles or knocks) that is paired to a jetaway 2 speed. It has a two barrel with stock intake and exhaust.

I want to build the car where it will run with the mustangs and camaros on the road (not the crazy high performance ones, just the typical V-8 versions), able to smoke both tires when I want to, but I would like it to have a decent highway capability as well to be able to cruise to car shows without filling up at every exit. Is that even possible?

If so, what would that entail? I was thinking...

Timing chain and gears
Intake and Carb (upgrade from 2 to 4bbl)
Cam
Valve job (as a part of the cam upgrade, if I understand it right)
Transmission
Headers / Dual Exhaust

If you were to do the the above, would you do it in a particular order or would you decide to do some in groups or would you wait to save your money and do it all at once...

Would you upgrade the suspension at all? Or, would factory replacements from Rock Auto be fine for the handling aspect of the car?

As I learn more about what others have done to their cars, I am finding that few seem to delve into the bottom end of the engine, just adding bigger cams, carbs, intakes, exhaust, etc. and paring that with a beefier transmission (getting rid of the jetaway 2 speed).

If you went through this process, would you please post what you did and what sequence you did it in? Maybe just links to those who have done this is all I need...

I am sure this is pretty ambiguous and wide open, but I am just a newbie that does not have anyone around me into cars whose brain I can pick. I have received some good private messages, but that correspondence has dried up - maybe I wore out my welcome. Anyway, any advice, help, examples and stories would help me greatly.

Have a good night all!

coppercutlass

I would upgrade the timing chain just because the original is not the best with those nylon gears. I would upgrade to a 4 barrel intake and carb go q jet ,fine tune the timing . I would add some headers and a good exhaust like the pypes system with an x pipe. But the biggest gain you would feel will be the rear end. Going from say 2.73 to a 3.42 will be a big bump in off the line performance you will feel. I would also go to a 3 speed trans th350 with a 2200 stall will also help liven things up in the performace dept. I wouldn't do too much to your engine . Imo I would buy a core build it over time . Upgrade everything else if need be like rear gear, trans, etc. All that can be used in a well planed future build and building a core will keep you on the road. The first time I did my car I did it all at once but I was restoring it ., that was rear gear , trans, and a mildly built 350 all planned out to work together . Ran 13's at the strip and held it's own on the street very well.

oldstata

Welcome !!!

Do you know what year the motor is ? I only ask because it could of been swapped out at some point

This is what I would do
1. Safety items brakes, steering, tires and lights
2. Springs,ball joints front end parts that maybe in question maybe do a steering box upgrade ( look into the jeep grand )
3. Depending on motor compression intake carb possible cam
4. Transmission / rear end gears/posi these need to be thought out and work together

Other will chime in on what they think, but this is how I would look at it. always remember that its a hobby and MAW always seem to kick in, so on the budget always plan on double what you think seems to help me

69ishHoliday

I just did exactly what you've listed to my 69 cutlass rocket 350. I did it all at once and it made an appreciable difference in the way my car runs. I'm leaning hard toward trading what would be acceptable fuel economy for a lower gear posi-trac rear to make the car quicker. Mileage is not important to me as I don't expect to drive this car any more than 1500 miles a year, just something to play with and improve. I found a good mechanic and spent $800 in labor for my upgrades and provided all of the parts. I think it was a great deal and was money well spent. - Steven

* I have not done any work to my transmission, it for now is a TH350.

m371961

I would start with intake and 4-barrel, dual exhaust/headers, see how you like that first. I would also evaluate engine with compression/leak down test before cam or head/valve work.

RetroRanger

As far as suspension I would replace all bushings, bearings ball joints and springs and shocks for the front and rear suspensions w moog or better parts. While that may sound like a tall order it will restore the suspension to at least the original as new working order and if you DIY it will run less than $500 with careful shopping. Assuming many current parts on your car are 40+ yrs old this will make positive difference you can feel. Once that's done I would add a 1.25" fr sway bar and a 1" rear swy bar, you may need to box the lower rear arms for the rear sway bar so plan on that before bushing replacement, one of my rear arms was bent so I replaced both w boxed units. Plan on at least $250-400 w careful shopping for a minimum you could go full hotchkiss but that stff costs ~$1200 to start.

With Ths stuff done I would add a jeep box or get the fast ratio rock auto box ( bolt in w new rag joint) ~$180

With all the above, for about $1k the car will handle and feel more like a new car, Once it drives nice then I would turn my attention to motor and gear mods.

This is what I've done w my cars suspension and it drives nice, steering is nice and tight and I can go fast around corners too!

Fun71

Changing from the 2 speed transmission to a 3 speed (or 4 speed) will give you a huge improvement in acceleration.

Similarly, a 4bbl carb and intake will be a huge improvement over the 2 bbl setup.

Smoking both rear tires means a limited slip rear, but I would not worry about that until you actually get to the point where you are overpowering the rear tires. Many 442s with 455 engines rolled off the line with open rears. Not saying it was optimal, but folks made it work.

1968CutlassSupreme

RetroRanger, when you say "all bushings, bearings, ball joints, springs and shocks" can you be a little more specific? I am very new and I don't even know what they look like (besides the shocks). Also, what does it mean to "box the lower rear arms?"

As for the "jeep box" what does that mean?

Off topic a little, does your car have drum all the way around? When I try to do a burnout, I can't even break the tires loose - it's almost like the brakes are holding too tight and I have drums all the way around.

1968CutlassSupreme

m371961, what kind of headers? Would you use the shorty or the full length? Would you use the magnaflow setup? How do I get a "leak down" test performed?

1968CutlassSupreme

Oldstata, the engine is a 1968 - the original engine. It has 106k miles on it. Runs strong as far as I can tell, strong pickup. No off the line ability - can't even break the tires going in a strait line (around a corner i can break one loose for about 20 feet or so).

Can you provide pictures or some visual for the "Springs,ball joints front end parts that maybe in question maybe do a steering box upgrade" because, though I know these are suspension parts, I have no idea where they go or what they look like.

How can I be sure to match the "Transmission / rear end gears/posi" - do you have any suggestions?

1968CutlassSupreme

Fun71, if i change to a four speed transmission, which i would love to do, i would need to change the shifter indicator from a two speed indicator (PRNDL) to a four speed (PRNDL21) in order to access the lower gears - can I just get this column from a later model car? How do I get a hold of a qjet and intake? And, of course, the all important question...does your car smoke both tires? :-)

oldstata

On the motor I would do a cam, intake, carb and timing chain.

If you went th350 or th400 3:23 /3:42 for a example

If you went 200r4 trans you could go steeper gears like 3:73/3:90 because of the overdrive it would rev lower at higher speeds
These are examples you would need to work with some one that knows a bit more than I do for every angle


Suspension front

A jeep steering box has a better turning. It's a poor mans fix but requires some research on your part to do it correctly

Ball joints are what holds the front upper/ lower control arms to the knuckle, these wear out and need replaced when they have excessive play. tie rods idler and pitman arms that have joints that can develop play over times. Any safety check should be able to let you know if these are bad ( if your state requires safety ) I would have some one check these or watch a few utube Videos to learn how to check your self

Hope this helps
Edit : if you go th350/400 I believe you could just use the same shifter the column might be loose enough to shift into or you just won't be able to use first manually. Sorry I don't know much on the 200r4

z11375ss

Rebuilding the suspension and doing the brakes will make your driving experience a whole new day. I have a friend with a stock by stock 67 GTO. I finally convinced him to change the parts mentioned above. The car is now a dream to drive so he says. No more drifting in and out of lanes and it stops straight and sure. Those things alone are worth doing first. I think you would enjoy the car that much more if you did just those things. Then on to the motor!

Stevec

IMO if your thinking of a cam,timing chain,carb,etc swap copper made a good point about getting a core and build that while still driving your current set up. Have reputable engine guy build you a short block,get a cam from Mark (CutlassEFI) and go from there.....

Fun71

The simplest swap would be to a 3 speed TH350 transmission. The 4 speed trans swap is a bit more involved with more complex issues. I know several folks in the local Olds Club who have gone from 2 speed to 3 speed on their '68s with minimal effort.

For the QJet and intake, that kinda depends upon where you are and what you want. There may be fellow Olds folks nearby that you could buy a factory intake and carb from, or you could have parts shipped to you. You could buy an aftermarket intake and carb (Edelbrock Performer 350 and carb). If you have good salvage yards, you may be able to find factory parts there.

Finally, yes, my car can smoke both rear tires. It always has, even before I did any work to anything. I found long ago that if you put skinny enough (or bald enough) tires on it, they will break loose!

oldcutlass

Looking at your car it looks like someone had spent some time and money on it in the past. It's very nice! Do you have a list of things that have been done to it before you got it? Some of the items mentioned in the previous posts may have already been done.


The reason it's not burning rubber may be as simple as a tune up. Your car already has dual exhaust, so that's a perk.


I don't like to throw parts on a car just for the sake of throwing on parts. First make sure what your replacing is worn out. I'd be willing to bet that the car is plenty drivable as it sits and that you can enjoy it while you start investigating what you want and then come up with a plan. Once you do that, start small and do one project at a time by reading the Chassis Manual and other literature.


Baby steps my friend, it's easy to get overwhelmed and frustrated if you get in over your head.

1968CutlassSupreme

Oldcutlass, it's like you are reading my mind! I am not driving it much (winter prep), but I am trying to research hardcore for the best way to go about getting the car the way I want it too. As far as the history goes, I really don't have any. I bought the car from a classic car dealer who bought it from the 2nd (i think) owner. As soon as I got it, I tuned it up (new plugs, wires, dist. cap, rotor, points). It runs pretty good, just not much umph off the line. I think the carburetor needs to be rebuilt because it's a two barrel and it has horrible gas mileage, and dumps fuel out the exhaust (black) until it warms up, then it clears up. It has an exhaust leak on the left side, but other than that ticking sound, the engine is smooth and quiet.

What I want to do is make it a street rod that can smoke 'em but can also cruise to the car shows.

A major problem is my lack of experience with old cars and their quirks and personality. I don't know how to do much and I still need to buy most of the basic tools needed.

oldcutlass

For experience, what could be better than just reading and jumping in there on the easier stuff first.


Ok, you said you started with a tune up, what is your dwell and timing set to? How did you adjust your carb and is the choke operating?


The exhaust leak is annoying, and I would fix that as my next project. I also would make the tail pipes a bit more presentable.


Do you have any friends with mechanical ability that would help you along the way? Like guys you meet at the local car shows, perhaps join a local Olds club if available?

1968CutlassSupreme

I have a friend who is very mechanically inclined, however his time is extremely limited most of the time. In fact, he did the majority of the tune up (the points especially) so I do not know where the dwell is (or even what that is). Speaking of that, what does a "dwell/tach" meter do? Someone suggested I pick one up as a part of a "standard tool set." The timing is set to "factory" - not advanced or retarded. The carb had to be adjusted leaner because it seems to be dumping fuel until it warms up. I do not think the choke is working properly, because it is closed most of the time, opening only about 1/4 inch after warm up.

As far as the exhaust leak, how do i fix it without replacing parts? If I need to replace the exhaust manifold, then I guess headers would be next up, right? The dual exhaust is true but it seems to be one side coming from a capped right side exhaust manifold (which may be where the leak is - the "cap" is actually a welded mess). Secondly, if I go to hedman headers (or any other, for that matter) do I need to use the regular length or the "shorty" headers? I am really confused at all the options - I don't know anything it seems.

The tailpipes are rusted on there. I figured I would change those out when I upgraded the exhaust system. How much am I looking at for a new exhaust system installed (approx)?

Thanks for the correspondence. I need lots of it.

oldcutlass

This link is for settings on your stock engine:


http://www.oldsmobility.com/old/tuneup.htm


As you can see your timing should be at 5 1/2 degrees before TDC with a dwell of 30. If your timing is as you described it will be a dog.

68conv455

Welcome to the site. Take things slow, fix one thing at a time. This will give you confidence as you take on progressively more difficult jobs. At one time, even the experts on this site were in the same boat as you.
I agree with some of the others above that safety should be a high priority. Brakes, steering, and suspension are very important. Make sure they are good. Fixing the annoying exhaust tick is pointless if you drive it into a pole because it doesn't stop safely.
After safety is good, your budget will help you determine your plan.

I think a 4.11 posi axle and a 2004R trans from a mid 80's buick grand national with a 2000 stall convertor is another way to help you achieve your goal of burnouts and cruising comfort without engine upgrades.

oldstata

Correct me if I am wrong, but that era of cutlass small block didn't have a true dual exhaust manifold. You could order with dual exhaust ,but the factory just capped the manifold on the cross over port ?

oldcutlass

You are correct and could expand that to almost all small blocks.

chrisneu68olds

Gotta get some documentation...
Go to http://wildaboutcars.com, sign up for free and grab the Assembly and Service Manual...and everything else you want to download. It is free and there is TONS of information there. You will find them under the Factory Publications link.

You are at the right place, most people on here are happy to share the information you seek.

billmerbach

I'd work from the bottom up

kitfoxdave

Sit down and decide how you plan to use the car. By saying Cruise to car shows, do you mean within an hour or two, or some big distances? We are all getting older everyday... comfort and reliability need to be considered. Of course smoking the tires a bit is a requirement!
My decisions were based on the following:
The engine and transmission were not matching to the car, so replacement was no big deal. I wanted torque more than HP (I do not need to wind it up to 6000 rpm!)
I wanted a fun car, (smoking tires) decided on a 380 stroker
200r4 built up transmission to take the additional torque, improve mileage (I plan to go on long cross country trips with this car
Guesstimate is about 20mpg...), and get it moving quickly.
Reliable!, safe (4 wheel discs when that mini stops quick in front of you), Comfortable. (Momma wants heated seats for back pain relief)
Stainless where it makes sense. (fuel lines, brake lines, exhaust) (I live near the Atlantic so salt fog is a concern)
And to have a GREAT looking car that is a BLAST to drive everywhere!


Will I have more money in it than I could get out of it? You better believe it!
Do I care? Not really. I have owned the car for almost 20 years now and would like to pass it on to my grandson one day...

coppercutlass

My 9 to 1 350 combo that was the first engine I had in my car was dead nuts reliable and I could drive it anywhere and it would turn 13.8's in the quarter and smoke the tires like no ones business. It got about 15 mpg with the 3.42's on the highway . That engine is now in my dads car . I couldn't bring my self to tearing into it. It was so reliable it was just jump in and drive.

olds 307 and 403

Do a compression test, make sure everything is good before dumping a bunch of money in it. If it isn't worn out, you just need matching springs for an upgraded cam. That said, W31 size valves and porting won't hurt. I would also replace the points with a Pertronix or similar points eliminator. It would also help recurving the distributor. I would pick up a Street Demon 625 carb and Performer manifold, Hooker Competition headers, dual exhaust, cam, matching springs, mild built 2004R with a 2000-2200 stall and 3.90 posi gears, if you can find them. Unfortunately Mustangs, Challengers and Camaro V6's are running what V8's ran a few years back.

coppercutlass

Unless it's an srt or something special a 13 sec car with good tq. Will give em a run for their money. I ran against a rt challanger he ran a 13.9 I ran 13.71 with that combo I mentioned.

Koda

Just out of curiosity, are you just hammering it from a stop, or power braking to burn out? Most 350s need the power brake in my experience, especially with highway gears.

Fun71

That hasn't been my experience.

It has a lot more to do with the rear tires than anything else, as in put some 295-50-15s out back and it will be really hard to break them loose. Put on some bald 185-80-14s and they will smoke until they pop.

1968CutlassSupreme

Thanks you all! Here's a question that may clarify what I am trying to do. What would it take to make this car able to smoke tires that are P215/70/14's? BTW, what do those numbers mean? Is 215 the width, 70 the height and 14 the diameter? Are these pretty decent sized tires or are they relatively normal and should be able to be lit up? I am really enjoying this correspondence you all! Thanks!

jag1886

I'd spend money on the drive train and suspension first, replace all the worn stuff in the suspension with stock replacement parts and add a larger sway bar to the front and just plain add one to the rear put some good shocks on it also. Then change the rear gear to something deeper in the 3:50- 3:70 range and upgrade to a 2004r OD transmission.
I only say this because the engine has a 106,000 miles on it. I'd definitely change the timing chain and upgrade the exhaust to at least duals if not so already, I don't think a 4BBl is going to help much with an old engine, I'd probably upgrade to a Holley 500 2BBl on the stock manifold.
These few upgrades will make your car perform so much better you won't believe it. Unfortunately once you start beating on it the engine will probably go away pretty fast, then I would do the cam and manifold when you rebuild the engine and when you do the engine the rest of the car will be ready for it.

1968CutlassSupreme

kitfoxdave, what I plan to use the car for is local (to NC) car shows, daily driving and the occasional trip to the strip (to beat on it a little... :-)). According to your description of what you want for your car, it pretty much matches mine, but I don't really want to change the engine. How difficult is it to change from drum to disc brakes?


jag1886 (and all who wish to chime in), is there a package that I can buy for the front suspension that has all of the parts (tie rod ends, idler and pitman arms, ball joints, bushings, bearings, springs, shocks, sway bar, etc) or would I have to buy them separately? I really feel bad about asking this, but is there any way someone could go to rockauto.com or something and paste links to the parts being mentioned?

I have the manuals for the car, but I am just now learning how to read it - most of it looks like chinese (all the pictures and tiny wording and stuff), so it's a slow go to find anything there - plus it has everything for all the models, including the 6cyl and the 8cyl stuff (over 1000 pages). It's going take some time for me to even get familiar with finding stuff (it's the CD pdf, so I can't just flip through it like a book).

You guys are great and I appreciate all the correspondence!

Fun71

I think it should be able to do that as it is. Not sure why it doesn't but I'm not there to look at it in person.

That's about it.
215 = width in mm
70 = aspect ratio (height is 70% of the 215mm width)
14 = wheel diameter in inches


That's a typical size tire for the era. Maybe a tad wider than what a Cutlass originally came off the line with, but around the same as what a 442 would have.
Back in the late '70s when my '70 Supreme was all bone-stock, including 2.56:1 rear end, it would smoke 225-70-15s with ease.

edit: I found that the 2 speed trans has a low gear ratio of 1.765:1 whereas the TH350 has a low gear ratio of 2.52:1, so that may be part of the reason your car doesn't spin the tires as easily.
Assuming a 2.56:1 ratio rear end on both cars, your car with the 2 speed would have 4.52:1 overall gear ratio vs. my car with a 3 speed had 6.45:1 overall gear ratio. That's a fairly significant difference.

jag1886

I wouldn't buy all the parts in the front end when only some of them are probably shot, unless you just plain want all new parts or are made of money. Take your car to a front end shop (almost any tire store) and have them tell you what is worn out and consider replacing all 4 coil springs at the same time, I know the 68 I owned in 75 drooped pretty bad so yours probably does also.
The front end shop was almost the first place I went after buying my 65 and all it needed was the center link, idler arm, control arm bushings and coil springs everything else was in good shape.

kitfoxdave

The front discs are an easy swap. You can do it in a few hours if you are completely new to this. Remeber to change the master cylinder and proportioning valve at the same. Rear discs are more involved.
Definately dovthe whole front suspension in one go. A couple of weekends for someone new to this. I know I did mine about 18 years back. HUGE difference in handling! The moog springs work great.

1968CutlassSupreme

kitfoxdave, thanks for the brakes info - now i just have to come up with about $650 for the parts (summitracing.com)...lol. Regarding the suspension, do I just buy two of everything (idler arm, bushings, tie rods, ball joints, coil springs, whatever else)? Should I just use Moog parts from Rock Auto or can I get good deals from somewhere else? Is there a way to buy this stuff as a package deal? I know I'm pretty ignorant, but I need help and you have to start somewhere right?

oldcutlass

The suggestion was made earlier in the thread to take it to a alignment shop that understands older cars. Not sears or pepboys type shops. Let them evaluate your front end and see which parts are bad, then just replace the bad ones. Looking at the pic's of your car, someone had maintained it prior to your ownership and those parts may have been changed already. Make educated decisions.

1968CutlassSupreme

Oldcutlass, I did see that recommendation, but there were others as well, and I just don't trust most people in my area. I don't even know where to begin to look for a shop that would know older cars. The reason I asked what I asked is because the car does not drive well - it drifts, there is tons of play in the steering wheel and (not necessarily related i know) it pulls hard to the right (sometimes) and to the left (at other times) when i brake. This has actually been a left turn in my thinking, because, if you remember, I began by talking about the engine and such, and then people began making recommendations about the suspension - and again I find myself lost. Thanks for your patience as I try to cut my teeth on auto mechanics.