Hey all, I recently picked up a 72 cutlass holiday project.
Came with the original 350 in it and I'm wondering what kind of horsepower a guy can get from this motor and still use it as a Dailey driver.

So far I am thinking of boring the block and putting some bigger pistons, new carb, cam, exhaust, go with 3.73 gearing in the rear I'm thinking.

I'm mainly wondering how this motor will perform once it's built up reasonably.
I'd hate to build it up and then wish I went with the 455 swap.

Not looking to build a drag car but would like something that wouldn't get pulled on by a new 1/2 ton hemi for example, haha.

So what's everyone doing to there rockets?

 

What octane of fuel? Get headers and higher stall 2200-2500 converter as well. DSS makes a decent piston.https://m.summitracing.com/parts/dms-6020x-4080 With minimal clean up on the head and block with the above pistons should put you around 9.6 to 1 with Felpro head gaskets. You would probably want a cam in the 220 duration range but I am no expert, Cutlassefi is the guy to contact. Keep it around .500" lift if using the stock non adjustable valve train. I would put 2.07"/1.625" valves in the stock heads, get them to use a bowl hog cutter to open the bowl bigger under valve and finish with a quality valve job with matching springs for the cam you choose. Get the either your Qjet custom tuned or a Street Demon or Quick fuel Slayer series carb, NO EDELBROCK.

 

I run a 355 with speed pro 5.8cc dish pistons, cam is 224/230 @ .050 .485/.490, 9.5:1 motor 3.73 rear and a 200-4r with a 2,400 stall. HEI with 35* timing and a quick fuel 750 and performer rpm, headers, x pipe etc. The car is a ton of fun, pulls hard at any rpm, will ignite the tires from a roll at any rpm in 1st gear, hasn't broke my eaton posi in a 7.5" rear (yet), no issues with mid grade fuel but I fun premium because it's not a daily.
Will idle all day in 100* heat and I have a sorry excuse for a radiator in there at the moment.
Things I'd do differently.

-Roller Cam

Things I intend to change

-Have heads cut for big valves (as stated)
-I'm getting a sniper efi kit, sooner than later.
If you can (I couldn't) I'd recommend a piston with a modern ring pack.

As for HP- never had it dyno'd but I'd be surprised if it was under 315/400 at the flywheel. BOL with your build

 

Those look very nice!

 

This the current build

355 Olds in my 72 cutlass

10 to 1 compression speed pro flat tops
lunati voodoo cam 522/539 lift 233/241 duration @ .050 lift
Prw roller rockers
Pro gear timing chain
#6 heads done by rocket racing just bowl work 2.07 in. 1.63 ex.
full length headers ,x pipe
34 degrees of timing on 93 octane
edelbrock performer rpm intake
holley 750 double pumper carb box stock
proform hei dist

crank is .010/.010, bore is .030 over bored with a tq. plate , it was balanced

Engine built by me


backed by a th350 Built by me with an ebay vendor 2800 stall converter and 3.90 gears out back.


Car is fully streetable , runs on pump gas and gets driven to the track and back 120 miles.

 

Yes they are but I've been working with them to try and change a few things on that piston. Namely, going to a thinner ring pack, getting rid of the valve reliefs and consequently just going with a small dish instead to name a few.

 

Good to hear Mark. They are already better than the Speedpro. Do you know the weight and clearance needed? I see they have the same compression height as the Speedpro pistons.

 

Appreciate all the detailed replies, have a lot to look into now and do some reading.

Have any of you ever put it on a dyno or ran some 1/4 miles? Would be interesting to hear some of your times.

EDIT: Coppercutlass I just seen your video, looks impressive! Makes me more and more excited watching things like that ha ha, thanks for sharing.

 

Mid 14's at the track with a way too small 204/214 cam for 9.5 to 1. Your car as is would be lucky to hit mid 15's as is. I would think even mid 13's would have quite good manners.

 

I ran 13.8's with a 260 h comp cams 212/212 447/447 lift and 9 to 1 compression.

 

Exactly, that is what most run. That was with my heavy marshmallow 88 Cutlass, a real struggle to even run better than 15's. I have a feeling my 70 with a 9 to 1 350 with a 214/214 cam will run circles around my 88.

 

I'm really wanting to hit that lower 13 mark atleast with this build. It sounds reasonably attainable would you say?

 

Yes, it is especially with a 2500 stall, a good one won't slip under light throttle and the 3.73's you are planning on. Definitely add full length 1 3/4" headers and 2.5" dual exhaust with a cross over pipe. A tuned to your motor carb and distributor will go a long way as well. You want 9 to 1+ compression, a cam probably in the 220 duration range, not an expert there and 2.07"/1.625" valves installed with the bowls opened up with a cutter and hand blending as well with the matching springs for your cam.

 

I went 13.02 with 1.875/1.562 valves in my 350.......zero porting. This was in a 78 Cutlass that weighed 3500 with me in it. Bottom end was bone stock from 1973. 9:1 compression, RPM intake, 221/230 cam, 650 holley dp, 3.73 gear, 200-4r trans with a 2200 stall.

I did an engine for a friend that went into his full dress 84 Delta (3800+ lbs) and that went 12.74 with another simple 350. This one was 10.2:1 compression, RPM intake, 650 holley dp, 230/236 cam, 2800 stall, th350 trans, 4.10 gear. This combo also sported stock small block heads with zero porting and 1.875/1.562 valves.

My 78 Cutlass was an awesome street car. You could cruise down the freeway at 75mph and you were only pulling 2400-2500rpms. I used it as my daily driver for a while. I won 17 bracket races with the car, including a series championship, and won 3 prestigious trophies with it (two NHRA Wallys and one IHRA Ironman).

I miss that car. Writing this post kind of lights a fire under my *** to get it going again.

 

First thing to consider is what daily driver is to you? And dont lie to yourself on this one.
What speeds are you seeing? Getting from Place A to Place B gets really old quickly if you have to drive 1,5 hours instead of 50mins via highway which you cant enter due to revs bothering you too much.

With 3.23 rear and 27" tires, im running 3000rpm and up on highway, 40mins per way to work. To summer cottage its almost 4 hours near 3000rpm's per way. Ive found it to be tolerable, not bad at all, but someone else, i quess, wouldnt mind that. If i would want to run steeper gear, i would go to OD trans instead of my TH350. Swapping trans is $$$$. What else you could do with that money?
I mentioned this just for sake of my former working buddy having 3.7x something gears and TF727. He couldnt stand driving highway with it. Sure, it was great on city area. But def not an DD. It dont see much use due to this very reason.

Plan the whole path once, then focus to accomplish it even if it takes years to do it.

 

…
Your cars run very well even with stock early heads. It seems cams with 220+ duration, 2200 minimum stall and 3.73 and up gearing seem to be the formula to go fast with a 350. I agree with both you on having OD with a car that sees any highway miles. I am still deciding between 3.42 and 3.90 gears to replace the 2.78 gears, running a 2004R of course.

 

I should have had much more stall with my 200-4r combination since it is a lockup converter. A 2800 stall would be the minimum if I were to do it all over again.

Run the 3.90 gear with a 27" or 28" tall tire. A taller tire will assist in traction and a small block will want more gear. More gear multiplies torque (but does not multiply hp), and a smaller displacement engine will need more to compensate for lack of torque production.

 

I see my custom cam is in the mail. I wanted very good manners, if my Wife or Daughter's drive the 70S. Mark ground me a 214/214 .472/.472 on a 110 LSA. I have a 2300 flash stall, rated at 2200-2500 converter and 2.78 gears will stay till next year. I am running manifolds and small duals till July, then 1 5/8" Sanderson's with a X pipe and 2.5" duals. I have a custom tuned 800 cfm QJet, Performer with a 1" open spacer, Magnetic Breakerless with a fast curve and a Mallory 6AL box to match. I am hoping to match my G body times even with worse gearing. I figure 2000 rpm at 60 mph with a P225/70R14 with 3.90's, sounds good to me and my 26x10.5-15 slicks will hopefully work OK. Please give your advice on my cam degreeing thread this week.

 

Hey all, I am new to the forum and have been doing some research - hence the reresection of an old thread.

I am building / tinkering on a one Owner (before me) 1977 Oldsmobile Cutlass Supreme Brougham - It has a 350 / 350 combo and I am wanting to make a cruiser out of it. I have a few questions.
How can one continue to run the AC (high idle solenoid) and still run aftermarket Intake Manifold and Carb? Also what else will be affected by going to a larger cam, headers, intake, carb, better HEI Dist., and such. I am looking for a better running and sounding street car - No racing just playing around town. I will also be re-gearing the horrible 2.41 to a 3.73 (another topic but I do believe it has a 7.5" not an 8.5" - Is that possible?).

Thanks in advance for any and all help.

 

First off, unless someone swapped the rear end, it will be a 8.5 rear. Seriously consider a TH2004R trans that will swap right in place of the TH350, just move the crossmember back. Fo it especially if long highway trips are planned. It will run similar rpm down the highway with 3.73 with the converter locked up as your current non lock up TH350 and 2.41. Also the 2004R factory converter stalls 300 rpm higher than the TH350. That and the better 2.74 first gear will improve performance. It will only need mild upgrades behind a 77 350. Even a 2.25" dual exhaust with manifolds will improve performance. The Thornton JR manifolds, their headers or Sanderson and Hedman shorty headers are an easier fit. The last two require custom down pipes. The Pypes down pipes will fit the Thornton manifolds and headers. It can be fun to install full length headers, things may need stuff under hood moved and sometimes the headers need tweaked to fit. If you are pulling the motor to rebuild, put the headers in before reinstalling the motor. A Performer intake, there is EGR and Non EGR available. It is basically a lighter intake manifold, most everything will swap from the stock #16 intake. The RPM is 2" taller and will actually increase performance, especially if a cam and compression increase is done. What are your goals with the motor? The 77-80 Olds 350 isn't the greatest starting point but will be OK, if kept mild. Get the 3A heads cracked checked, a known issue and they will need porting especially on the exhaust side and bigger valves. Early heads are a better starting point and have smaller chambers. Your stock block is a windowed main, which is weaker with a weak crank. Pistons will depend on head and power goals. You can upgrade the cam and still kerp near factory manners. Get the factory 800 cfm Qjet retuned to match any motor upgrades. Good luck.

 

Thank you very much.
It will be a street cruiser - Play Toy, No racing.
Looking for around 350 HP, would like to use the stock bottom end due to it only having 43xxx miles and running flawlessly.
I am really just looking to sound good and turn some heads while running with the Mild Built SBC Nova's and Chevelle's around the area.

It will mainly be used for car shows and cruise nights and Sunday drives.

 

You will have 14cc pistons .025", below deck, give or take. Edelbrock is releasing a new 68cc head shortly that allows a mechanical fuel pump but it needs the RPM intake. Or find #2 through 7A heads and get them milled and ported with W31 valves. The converter should be a lock up stalled to work with whatever cam you choose. The 218/218 duration roller cam, I got from Cutlassefi should hit that 350 HP number with iron heads but they are pricey to run, in the $1000 US range with just the cam and lifters.