Supremely72

Hello all, I got a 1972 Cutlass Supreme with a 350/350. She runs pretty good but I'm always wanting more. PO did a cam and top end work, but otherwise a stock th350 and stock 1-legger 2.73 gear 10 bolt. I've accumulated 2 455's. A 73-76, I got for free. J heads emmisions 4 barrel intake it had 2 bent pushrods and whatever idiot dismantled it tried to cut the balancer off and trashed the crank snout with it. Block and bores are perfect. And he had a NIB mild flat tappet comp cam brand new I got with it for free and sold it for $150 (score). Last week I grabbed a 4 barrel 455 from a 1968 delta 88, ac/ps/pb with cruise and C heads. No trans with it, been sitting for about 15 years. Tore it right down today. Just one dry seized piston and all original bottom end, N crank. In good shape. With that seized piston out and oil in the cylinders it spun around butter smooth.

My build up ideas have a few requirements, I want it to be streetable and maintain my PB. Must be a roller cam, ideally roller rockers.
Starting with crank. Get it the ol' .010 / .010
Stock rods balanced and stress risers ground
Looking for pistons to end up with a 10:1 comp ratio. Needs to run on pump gas, mostly available around here is 87. 91 at some stations which I'd be alright with
Have the block cleaned and line (align? Seen it both ways) bored, decked to perhaps .005? Bored over .030 or .060 see what the machinist recommends.
Stock oil pump, deep oil pan
Restrictor pushrods and restrictors in the block
Comp Cams XR276HR (hydraulic roller), good from 1800-5600 rpm with double roller timing chain
I'm torn between going roller rockers and aluminum edelbrock heads, since they come pre-assembled with valves/hardware, flow better, high comp, no risers to fill. Or keeping the stock C heads and stock rocker arms etc, I'd need new springs. Will need have all machine work done aswell, to get springs to use with roller cam. Leaning towards the edelbrocks
Looking at harland sharp roller rockers. However I hear they won't fit under stock valve covers. My valve covers are also not notched. I'd like to be able to have some clearance to keep the power brakes I got now.
Going to get an edelbrock performer air gap intake
Going to go with a holley sniper efi, with a holley dual sync distro and coil, to let the sniper control the timing
Fuel pump block off and order a holley tank with intank electric pump.
I would like NEED headers, need recommendations for what would fit a 72 Supreme.

No AC, so won't be using it. Mostly missing from the engine anyways.

Have a th400 I picked up from a 1968 impala. Do a rebuild, a transgo 1-2 shift kit, I'll keep it more mild on the drill bits. HD sprag upgrade. Rollerize rear thrust bearing. Use a bellhousing adapter. Go with a 2200 stall torque converter.

Rear end I need help with part numbers or what to do there. Have a gm 8.5 10 bolt stock for a 72 cutlass. 2.73 gears 1 legger. I'd like to go posi with 3.08 or 3.23. I do a bit of highway and roadtrip (110km max - 70mph).

Colling will be an Electric water pump, dual electric fan setup from a windstar with a 4 core rad (rad recommendations welcome)

I mostly value reliable and ease of operation, and value tire burning directly there after. I want to to be able to cruise with manners but be able to shred tires and go real quick when I want it to. Maybe I'm going overboard. I'd like to get 450-500hp and high 500 ft lbs or more torque. Tell me what you think of my overall build idea or if maybe it's too much for a street car, or maybe just alum heads are too overboard, valve train too overboard? Thanks in advance guys

matt69olds

Wow, you have done some research. Good thinking.

I have said it many times, get the best/lightest pistons you can. Mahle and CP are good choices, anything you can do to keep the rotating light helps keep the short block together

i have edelbrock heads on my engine, Harlan sharp rockers, with stock valve covers. I bought 3/8 spacers for extra clearance, the fit with no trouble.

I would skip the electric water pump. The rest of the cooling system plans sound good.

Find a machinist your comfortable with, preferably someone familiar with Olds. Olds engines need loose bearing clearances. If your machinist argues with you, find another shop. If you assemble it with the typical sbc way of doing things, the engine will “clearance” itself, with the extra bearing material ending up in the pan or oil filter.

Im using a smaller than factory brake booster, I got it from a swap meet so I have no clue what the original application was. I can tell you I have no problem running power brakes with the hairy cam.

Hooker headers are about the best bang for the buck. The fit my car perfectly, no dents needed. I did move the brake distribution block to the top of the frame when I made new brake lines, that’s the only issue most people have. There are other much more expensive headers out there, maybe when my hookers are done I’ll look into them.

I would go with the edlebrock heads. It’s pretty difficult to properly rebuild iron heads and not sink some big money into them. By the time you clean the heads, check for cracks, replace guides, buy springs, machine the heads for the rocker studs, then the valve job, etc, your probably pretty close the the cost of aftermarket heads. Then factor in the bolt on 50 hp the edlebrocks provide over the stock iron,it’s a no brainer.

matt69olds

Wow, you have done some research. Good thinking.

I have said it many times, get the best/lightest pistons you can. Mahle and CP are good choices, anything you can do to keep the rotating light helps keep the short block together

i have edelbrock heads on my engine, Harlan sharp rockers, with stock valve covers. I bought 3/8 spacers for extra clearance, the fit with no trouble.

I would skip the electric water pump. The rest of the cooling system plans sound good.

Find a machinist your comfortable with, preferably someone familiar with Olds. Olds engines need loose bearing clearances. If your machinist argues with you, find another shop. If you assemble it with the typical sbc way of doing things, the engine will “clearance” itself, with the extra bearing material ending up in the pan or oil filter.

Im using a smaller than factory brake booster, I got it from a swap meet so I have no clue what the original application was. I can tell you I have no problem running power brakes with the hairy cam.

Hooker headers are about the best bang for the buck. The fit my car perfectly, no dents needed. I did move the brake distribution block to the top of the frame when I made new brake lines, that’s the only issue most people have. There are other much more expensive headers out there, maybe when my hookers are done I’ll look into them.

I would go with the edlebrock heads. It’s pretty difficult to properly rebuild iron heads and not sink some big money into them. By the time you clean the heads, check for cracks, replace guides, buy springs, machine the heads for the rocker studs, then the valve job, etc, your probably pretty close the the cost of aftermarket heads. Then factor in the bolt on 50 hp the edlebrocks provide over the stock iron,it’s a no brainer.

jmos4

Hi,

A 68 impala/Chevy trans has a different bell housing pattern you need one from a Buick, Olds or Pontiac, and I believe Cadillac as well

Regards,

Supremely72

You're right they are different bellhousing, however BOP with short tailshaft are very few and far between in my neck of the woods (Northern Saskatchewan, Canada) and a pattern adapter is only about $80 usd.

matt69olds

Sell the Chevy trans, use the funds to get a BOP 400. The BOP stuff is pretty easy to find.

I build slot of transmissions, I have people bring me a Chevy case and want the behousing cut off to use a Ultrabell to adapt the GM trans to use behind a late model Hemi of ford engine. I keep the Chevy cases, and cut a BOP case instead. Only way I cut up a Chevy case is if it’s got a badly cracked bellhousing.

If your reasonably comfortable with transmission work, save your money on the TransGo kit. You can get better results for next to nothing with some easy modifications.

Supremely72

I've been searching for months in my province. Have found a single long tail shaft BOP. I don't mean to cut the bellhousing off and adapt it that way, but an adapter plate. such as https://www.jegs.com/i/JEGS/555/60172/10002/-1
My current olds 350 is using a chevy th350 with a similar adapter plate, done by some previous owner long ago

cutlassefi

The first thing you need to decide is your budget. That will obviously dictate the majority of what you buy.
From there you can do either the Edelbrock heads, or the Procomp Heads, I offer a reworked version of those.
If you end up using a roller cam, you most likely will not be able to use the stock type rocker arm. The roller cam profiles are typically just too aggressive, and have more lift than the stock rocker system is designed to handle.
matt69 is right, use the H beam rods with a good aftermarket piston. If you’re only going .030 over, then you can use the Wiseco. Otherwise you’ll need to use either the CP or one that I do from Race Tech.
Hope this helps.