Hello, i have a 1976 Oldsmobile Cutlass 442 with numbers matching 350 with 95k Original Miles. The 350 has an Edelbrock Performer Intake Manifold, Hedman Long Tube Headers to X Pipe with Flowmaster 50s with a Quick Fuel 600cfm Slayer to top off the Cake.. (not including K&N Airfilter, Accel Wires and Brad Penn Oil)

What i want to do is make it a quick little Street Machine.. (14 Second 1/4 mile, 6.6-7 Seconds 0-60 Car). Could i get there with a 10 bolt 3.42 Posi and some Edelbrock Aluminum Heads? Does this 76 350 have 14cc Pistons? The Compression is all around 120 for each Cylinder.

 

Change to at least a 3.42 rear, lose the 600 and regular Performer and replace them with a 750 and RPM. Get a set of 5, 6, or 7 heads and a mild cam and you'll reach your goals.

 

Get rid of the Quick Fuel? This is suppose to be one of the best Carbs on the market? and the Stock Iron Heads would be better than Aluminums?

 

3.42 or 3.73 gears as 3.55 does not exist for the corporate 8.5" 10 bolt.

 

3.42 Thats it! Why was i typing 3.55s... i knew something didnt sound right.. Ford Gears..

 

You are pretty close to don 80rocket and 67cutlassfreak the cylinder head guru . That 76 is heavy and i would gear it as much as you would be comfortable with. I had a nice little combo that went 13.86 in my 72 . It was a 73 350 with the 14cc dish which yours should have. It had 72 7a heads just freshened up , edelbrock intake (performer) 600 cfm carb , comp cams 260 h cam compression was appx. 9 to 1. full length headers , x pipe ,hooker aero chamber mufflers, proform hei , th400 with a 2200 stall and 3.73 gears . The th350 will free up some hp.

Im currently running 12.9's with iron heads with just big valves so you dont need aluminums for your goals. kind of a waste of money. Im currently running 12.9's and i have under 4k into the whole engine thats with me buying swap meet stuff and building it myself. Its a 355 pretty basic build kind of generic but it works.

FWIW i ran 13.3's @ 103 with a little 600cfm carb. A few weeks ago i ran an 830 cfm and the fastest we went was a 13.09 @ 103 . of course we had a slight stumble off the line killing my 60 ft but i put the 750 back on and ran a 12.91 @ 103 on the second pass. The mph between the 830 and the 750 was the same., my mph with the 600 cfm was 103 mph same as with all the other carbs . If there are performance gains to be had you usually go by mph. Just my observation about cfms and on track performance. On the dyno its a diffrent story

 

i want it to be a highway car (for trips) so would the 3.42 be more convenient? i thought the Aluminum heads were a big upgrade? especially for an Engine like mine? Should i just have my stock iron heads redone? im not sure what number heads they are? im thinking 5s..?

 

A 3.42 gear is good . The aluminums will cost more. Some 5's , 6's or 7's will be fine. Just get big valves and bowl work done. You don't need aluminum heads for your goals. I spent 1600 on my current top end. That's intake rockers , valves, heads being reworked etc etc . I went 13.86 with stone stock 7a heads just freshened up.

 

The RPM heads are good but have 2 issues on the SBO. One is even with flat tops, you have 9 to 1 compression due to the large 77cc chambers. Second is a mechanical fuel pump can't be used. I would mill whatever heads you use to reach 9 to 1. The rpm is a better performance intake and a 750 carb is better, a 600 will probably be too small. Either go Street Demon 750 or a Quick fuel 750 Slayer series.

 

I beg to differ on the carb size. Like I said . 3 diffrent carb sizes same mph . I ran 13.86 with a 600 cfm and went 13.3 with a 600 cfm carb. He already has the performer so it will be sufficient for his goals. On my current 355 I tried an 830 off the line it had a stumble but the best mph we saw was 103 mph we went down to a 750 and mph is still the same. I'm tempted to go down to a 650. A smaller carb will have better throttle response. My 60 ft times are what makes or brakes a good e\t the mph is always the same . If my mph falls then I need more but I doubt it considering I had the same mph with a 600 cfm carb on a similar combo in the past. If gains are to be had you go by the mph not the e\t so based on that I went 13.3 at 103 with a 600 cfm carb. Its safe to say it was enough carb since I'm still trapping at 103 but running 12.9's with a 750 cfm carb.

 

I stand by the Street Demon 750, very similar to a Qjet, uses whatever it needs for air flow. Small, very precise primary metering. I don't run Holley style carbs, never will, leave that to you. I found the same thing the last time out, my 60 ft was the difference between my best and worst run.

 

That's fine if the cfm will vary depending on engine load but he already has the 600 cfm . It will work. My holley is a box stock 3310 750 cfm.

 

Use a vacuum gauge to check for cfm restriction. Hook it up to manifold vacuum & drive the car hard. If you get a reading of vacuum at wot then the carb might be too small.

 

I am with copper on this one.The guy has the carb might as well use it.Should be fine for what the op wants.

 

X2, perfect. I'll bet it has 3" or better. I did a mild 380 with an RPM and 750 Slayer. At wot it was pulling almost 2" of vacuum. I'll bet that 600 will be too small for the combination.

 

You might be right but think about this. He has the parts and only looking for 14 seconds 1/4 and a high thirteen is a bonus. I think he has all he needs for a 350 ci mild engine.

 

Your compression readings are low, original head gaskets? I had 140-142 psi all 8 cylinders on my stock 76 350 with the exception of the compression bleeding Performer cam advanced 2 degrees on the Cloyes Street roller set. But just don't think it will instantly fly down the track. A lot guys fall well short at our track, first time out. I ran 11.3-10.6 in the 1/8 first time out, was stuck at 9.7 forever, now 9.4 and falling. You need something better than a stock converter. Find early heads and mill to 60cc, will put you at 9 to 1 with cheap Felpro head gaskets. Yes, his existing parts will work with his goals, especially being mostly a street cruiser. Don't forget his car is 4000+ pounds, doesn't help.

 

I'm a $/HP guy. What is considered cheap?
Performer RPM heads= 1,100
1-1,100 will net you forged pistons and machine work for the cyl walls/square the deck. The car has 100k-ish on it and would probably benefit from new oil pump, timing chain etc before any internal performance upgrades are accomplished. (I.e bigger cam, head swap, boost in compression).
2- Once the heads come off you're at the mercy of a thicker gasket as Christian stated. aprox .039, I don't know where a stock 14cc cast piston sits in the hole but using .025..you'll need to mill the heads which is more machine work. Upgrade in the piston department would make this unneeded to achieve 9.1. (5.8cc dish speed pros, .025 in hole, .039 gasket, 68cc heads [which is an abnormally high number in my research] nets you a nice streetable 9.2:1]
3- 3.42+ turbo 350 + 255/605/15 tires= 65mph @ 2,750 rpms.
4- Carb- I'm not an expert, I bought what Mark suggested and tuned it to my application and I absolutely love it. Is 600 enough? Only one way to find out and if you can't get the uupmh then summit will send you a shiny new 750 for 300 bucks.

If your goals are specific, I recommend a specific build. Just my .02.

 

My .02

Olds engines "like" big carbs, Buick as well

He is not going to hit 14.0 without some gear, if he wants the best of both worlds, build a 7004R Even with the gear, in a tank like that it will take a well-thought out combo, probably won't get there with a tired lower end.

 

If he upgrades the pistons to flat top, he can use his #8 heads, milled slightly and good bowl clean up on the exhaust side especially.

 

he can probably get away with re ringing the bottom end if things check out then just get some better heads. Im gonna talk to 67cutlassfreak he had some #3 heads i left at his place he might be able to rebuild them for you as a resonable price.

 

Factory heads for the 73-76 350 engines was #8, which have larger combustion chambers to achieve the same 8.5:1 compression ratio that the 71-72 engines had with deep dish pistons.

 

Give this a chew:
flat top speed pros- $315
http://www.summitracing.com/parts/sl...ake/oldsmobile
new rings- $80
http://www.summitracing.com/parts/sl...7k30/overview/

Good machine shop to do the block and mill the stock heads, timing set, cam lifters, oil pump- $ hard to say, I'm going to estimate 1,400 but there are a lot of builders on CO and they will have a better estimate. Makes a fun winter project and next summer you got yourself a much stronger street machine with a new timing chain/oil pump before you turn 100k on the clock.

What rear is in there now? It’s a Gm 10 bolt and you have other options if you want a high way car. 3.08, 3.23. Couple those with a fresh flat top 350, QF, performer and your header back system and you’d have a nice torquey street machine that cruises at 60mph turning 2,300 rpms (255/60r/15 tire)

 

So pretty much i should just have this 350 rebuilt..?

 

No! you can build a nice runner with what you have you can re ring the bottom end throw some #5 heads or smaller chamber heads a nice cam and you will have a nice runner. I build all my engines. I farm out the machine work and do assembly and all that stuff my self. Too many chefs ruin the stew. Im glad i built my first engine before i was on any forums becasue everyone say's have it built but we see so many stories of failure within a short amount of time. My current 355 started out as a swap meet 355 core with flat tops . currently runs 12.80's and i beat on it hard and drive it to the track and back., i built it in my garage and i built my own trans ., dont get me wrong it took some work but i still have alot less into it that if i payed a shop to build it. if you keep it cheap and build it yourself you will learn more. if may not be a forever engine but you will learn what works and what does not.


Fwiw im pro for doing your own stuff. you get guys who come on here and spend a lot of money and end up with either underperfomring engines or failure. it happens like clockwork around here .

 

lead me into the right direction! i went to Drag Week today at the Grove and it inspired me so much to get my Oldsmobile that way.. I would start tomorrow i just need to know where to go.

 

My buddy was there today . What i would do is get your engine out measure the bores , pistons and the rod and main journals. If you can get away with it re ring it. I would have the block deck surface milled to have the piston sit .010 in the bore. then find some good heads like #5's have them milled to a true 64 cc use a .028 head gasket and you will have 9.3 to 1 compression. The cam choice will come down to gear , converter , wheight of the car and useage .

My little 350 that ran 13.8's was built just as i explained and it still running and in my dads car.

 

3.42 gears with Posi, not sure on converter (know nothing about em) and occasional sunny day Driver/Strip (Soon to be Hopefully)

 

A 2500 stall will work good with most cams that will suit your build. You can have your stock converter re flashed. I like torque converter technologies in villa park il . My suggestion to you would be to find a nice runner. Member octania was sellinf a nice 403 with #5 heads and trans for under 1500 and it ran and drove. You could build up the 350 or the 403 and keep your car on the street this way you can take your time and do things right and not rush yourself.

 

By the time he does all that he is right at where he would be doing it the way BOSS suggested, which I agree with. That way he can use the heads he already has and will have better pistons and proper clearances. You do not know the condition of the engine, nobody does. Just because a machine shop does some work does not mean he isn't "building" it himself.

 

Jim im not saying boss was wrong. But the the #8 heads will need money and work too. much more work considering the choke points under the valve. If he invest some money in the a set of #5's they can be reused down the road. I did that in the past . a re ring kit is about 200 on ebay. You can buy the pistons (400) then you have to pay to R&r (80) then then balance (180) , bore and hone (250-300) , so that 400 dollar set of pistons just cost you wayyyy more that 400. For 400 you can re ring a short block and have some money left over for a cam. The short block im working on now i have 1500 in machining alone ! and they honed the cylinders not even bored them since it was already .030 over and the crank was polished. I built my little 350 that went 13.86 with 2500 that was carb to oil pan. Like i said before its still running strong.

The whole (build it himself) comment was thrown out there becasue alot of people like to send their stuff out and spend 6500 for an engine like i have now that cost me 4k and that including me fixing the cam issue i had . Im running 12.80's some guys spend more and cant even touch that.


Jim i have built them cheap , I have built them in the middle of the road price wise , and the one im currently working on is just a money pit compared to anything else i have built. had i not gotten that short block for free and cutlass freak ported the heads as a trade i would be 6500 into this 355 im working on currently and i still need a few things to finish it . I have built from one end of the spectrum to the other and have achived goals many have not and they spent more. take it with a grain of salt.

 

Take this for what its worth. My current engine is nothing special , Its was built to hit certain goals and that taken into consideration i built it with what ever i had and could get. Its about as unsophisticated as it gets . On paper its pretty generic. there is no real tuning on it . Its got a box stock 750 holley on it which i havent even touched. I see so many people who have their engines built and they under perform or dont work right or make too much noise. I would hate to spend that money and be left empty handed.

 

i do appreciate all of the replies to my questions.. I will take all of this valuable information and get to work. i do have a machine shop that will hook me up on this first build of mine. Thank you very much everyone... Was thinking Posi 3.42, 2600 Converter, Maybe keep the Current Heads or 5s and a nice mild cam. Hopefully she flies! all up to me now on when i wanna dig this thing outta my car...

 

As always, it comes down to two questions, what are your goals and what is your budget? For $1000 +/- you can get some older 350 heads, get a good valve job and a little port work, bolt them on along with a cam as Mark suggested in post #2 of this thread. Pop in some gears and you will have a fun little (well, BIG actually) cruiser that should run a low 14 and be fun to drive.

If you are going to rebuild it, IMO, do it right, with good parts and machine work. For this you are looking at $6000 +/- Your money, your call!

 

I agree with jim. If you do it right get the flat tops and you can use your #8 heads. My suggestion is if you have a light budget and want to learn and get your feet wet ., what works what does not this way if you do make a mistake its not costly. In your situation have your machine shop show you what they are doing if possible and why

 

I wouldn't bother re-ringing and bearings, if they need replaced, probably need machine work. As said, early heads, milled with bowl work and a good valve job will get you there with right cam, converter and gears.

 

im 19 so i do not have the biggest budget probably around 1500$, My Goal is to have a bad *** 70s Street Machine that runs high 13s low 14s.

 

Why wouldn't you re ring it @olds307and403 ??? If everything specs out whynot ? I recently measured a 350 that had seen use andthe biggest tolerance was .0055 . It would last long enough for some good use. Like many of us I constantly change stuff. So if I can get 2 years from one combo its good and gives me time to build something else. Got my car running good and I'm in the finishing stages of my 355 build. I don't think I have had an engine in my car longer than 2 years. My point being you can build something for now with a limited budget , learn see what it does and when money allows build it even better. He has a very limited budget and what you guys are suggesting won't cover a "good" short block even if the machine show is hooking the work up for free. You gotta factor in cam , bearings , rings , oil pump , timing chain , gaskets , and just like that a huge chunk of your budget is blown. There is nothing wrong with re ringing. I went 13.3's @ 103 with a re ringed 350 using old cast flat tops . After 2 years and hard abuse I started hearing some faint noises and I cracked 4 piston skirts. My loss ? Was 500 bucks but I got 2 years out of it . I had the engine I have now in the works and that was that . Its not meant to be for ever when its built that way but knowledge and experience can be gained . I re used many of the components from that 350 like the pan , oil pump and a few odds and ends on my current engine and I sold the block , cam and recently the pistons that where not cracked. Some guys like to complain but I learned a lot from my previous builds , what's good what's not . I'm sorry but at 19 I didn't have much money so I had to make do so I built what I could .

 

Someone please make this a sticky", I can't even guess at how many times I have read the exact same thing. Jeez. Enough already.

I agree with 307/403, either rebuild it correctly or just leave it alone and bolt some early 350 heads on it. No need to open a can of worms.

 

Look im just explaining my first hand experience. You guys beat the same drum as much as i do. Im just sharing my experience what can be done what can happen etc etc. I atleast post something else besides buy all new parts or its wrong.