I am trying to decide which engine to put back into my blue 72 cutlass S.
So everyone gets a vote, I have some specs on the motors. My concern is I will put the 455 in and the performance will only be marginally better then the 350. I and my grandson want to do this right the first time through.

I purchased the car in March. Sooo! Long story short , I thought the 350 was bad. It was using a lot of oil and smoking, especially the right bank. Well, I am still kicking myself over this one. When I finally changed the oil before a 200 mile run to a car show, I found the dip stick was marked wrong. It was an aftermarket stick and well it was about 2 quarts over full. So I was topping her off. With the correct oil, 5 quarts its hardly using any oil and no smoking. Beware the dip stick!!!

My plans are to put a 200-4r behind one of these motors. The rear gear is a 3.08 open carrier. Maganaflow 2.5" exhaust and mufflers. If I go with the 455 I will need to buy headers and probably cut the H pipe on the exhausts to make it fit. any thoughts on this ?

Of course I seized the opportunity to purchase a 72 olds 455 rebuilt with about 16k miles on it, been setting for about 6 years, started some during this time, originally in a 72 wagon he owned. I bought the whole car(78 88) he had stuffed it in. The original owner (mechanic) rebuilt the engine. I drove the car and it run good considering it had cats and quite exhaust, a little blow by, but otherwise good. I feel the 750 holley is over jetted for this motor, he just put it on to sell it. So it wasn't tuned for the motor.

The 455 engine has the edlebrock 2152 cam kit, 2151 intake, 750 holley Gm HEI and standard dished pistons (assume stock). With about 16k miles, possible more miles since the valves and valve covers had more film on them then I would expect for a engine with 16 k miles. All plugs are black. Here are the compression and leak down tests, all leak down test was done with 100 psi.
cyl, compression , leak down pressure ,% leakage
1 135 92 8
8 130 92 8
4 130 95 5
3 135 95 5
6 130 90 10
5 137 95 5
7 137 90 10
2 130 90 10

the 350 engine has an edlebrock rpm intake, hooker headers 2.5", 650 holley, nice cam, little thump! don't have specs, pertronix hei distributor. Chrome pan, valve covers, etc.The rocker assemblies are very clean, it doesn't appear to have many hours on this motor. Plugs now look ok, 1 and 8 look right, all rest appear to be running a little rich (blacker and darker tan). It has dish pistons also, assume stock. Here are the numbers

cyl, compression, leak down pressure, % leakage
1 145 98 2
8 150 98 2
4 155 98 2
3 140 99 1
6 145 100 0
5 140 100 0
7 140 96 4
2 140 97 3

Both engines are out, My grandson wanted to learn how to pull them, so he helped with both. We still need to move the brake proportional valve as it is to close to the header for my liking. And repair the air conditioning box, as it is destroyed, not by us. Although we are some what dangerous with all that engine and tranny weight moving around.

So please give me your opinion, hints, tricks, concerns based on what I know about the engine and goals. All input is appreciated.

 

I'm a fan of the big blocks.
Of course you will need the frame mounts from
the doner car, or use your small block motor mounts.
A shorttail 400 turbo tranny. The 350 turbo won't live
long behind a big block. Don't toss the driveshaft of the
big car, you will need the yolk for the 400. Good luck
on your decision. Sounds like fun with your grandson.

 

Either one will work fine, but I'm with Adam. Not much difference in gas milage but when you mash the gas pedal you'll feel the torque difference between the big block and the small block. Since you have the engines out of the car already I'd go with the 455. John

 

I like BB's, because of the awe n fun factor! It all boils down to what you want.

 

Kinda hard to argue with 500 ft-lbs of torque, stock. Weight difference between the SBO and BBO is under 50 lbs, so that's a non-issue.

 

Thanks guys for your input. I am going to post this over on the engine forum to see if I can get some more input.

 

Moved the brake proportional valve from side rail to the top. Amazingly I was able to connect up all the brake lines without cutting or adding lines. Bled the brakes and replaced most of the ugly fluid with fresh fluid. Now I am ready for either engine. At least I won't be frying the brake fluid with the headers.

While I have the engine out, I am working on repairing the air conditioner / heater box. The original was destroyed. Some fiberglass repair on the used one , sanding coat of paint and ready to finish tomorrow.

going to test fit the 454 with 200r4 on Sat to see how the orginal headers and transmission mounts up.

 

The 200 4R is bascally the same format as the 350.
Same length, driveshaft.
If you are going to use it, have it built! A 350 will last longer
than an underbuilt 200.

 

It was rebuilt by a local builder here , who builds these and other trannys for the street cars & drag racers here in Bristol, tn area. (Nascar motor speedway and Thunder valley dragway) Told him the application I was using it for , he insures me it will last. Gave me a 6 month warranty, of course its been setting in the garage for the last 2 months eating away at the warranty. Hope to have it all by together in the next 2 weeks.

 

I'd go with the 455, for torque reasons and the thought of having a BB 7.5L. IMO, bigger is better. Oh yeah!!!

 

how much and where did you find a 455?

 

You had BETTER mean 455.............