My 1970 has the Heart of a '73

[Coltonis]

Hello! Alrighty this is a lot of firsts for me: First post, First Oldsmobile, and (Possibly) First Engine Re-Build! And have I got a doozy for ya... I just bought a 1970 Cutlass with a 455 . Yay ME! I got to checking block numbers and its an Fa block this means its 1972+ block. (Feel free to correct me if I'm wrong along the way here...) So I wanted to be sure its a 72 block so 4 hours and a lot of Goof Off later I managed to find the VIN derivative beneath a hasty engine paint job from a previous owner. 33M..... this means 3=olds 3=1973 block M= Lansing Michigan. Ugh, so I looked up specs on 73 engines and all I could find was 250hp, not the 365hp and ~500ft/lb of torque that a 1970 engine woud have...Enter disapointment. Now interesting thing is it has E heads! If my googling is correct, E heads were only 1970. Lol...What should I expect from this beast? (its not quite running yet..) Are the E heads gonna make a huge diference? What kind of torque did the 73's have? Anyone know what was the limiting factors for 73 455's? Is it worth rebuilding this engine or would I be better off finding a true 1970 block? Any and all Advice, Suggestions, or Opinions are welcome!

I realise my info might be a bit sparse, but: For sure its got a Quadrajet carb and an AT tranny, I've been told its a TH400, not sure on its backend gearing and as for inside the engine (pistons,cams, etc.)-- no idea -- assuming stock-- haven't stripped it down yet...

P.S. Its Soooooo PRETTY! LoL!

[Oldsguy]

Well, I want to welcome you to our site first off and second, I want to say that I would rebuild a '73 engine especially if it had E heads. Since it does have E heads you should ask yourself why or how could that be? Maybe someon has already rebuilt the engine or at least changed heads which means factory specs are out the window. The biggest difference between '70 and '73 was the statci compression ratio, it was less in '73. At any rate, go with what you have.

[GoldOlds]

Originally Posted by Coltonis

Is it worth rebuilding this engine or would I be better off finding a true 1970 block?

Any 455 that isn't cracked or been bored over too much is worth rebuilding. There's nothing wrong with E heads; I'd keep 'em. Assuming everything is original except the heads (warning: it's never good to assume), you'll probably want more compression-friendly pistons. By '73, the dish in the factory pistons got deeper. Bottom line: ALL Olds 455 engines have great potential to make a lot of power - especially bottom end torque.
Oh, and congrats on the purchase!

- GoldOlds

[dar83501]

I've never heard of Oldsmobile putting a 455 in any vehicle without a turbo-400 backing it. 265 horses i've also never heard of in a 455... it should be at least 300 even if it's a smog motor, and at LEAST 375 ft.lbs of torque...and i'm being extremely ungenerous here.

[joe_padavano]

Originally Posted by dar83501

I've never heard of Oldsmobile putting a 455 in any vehicle without a turbo-400 backing it. 265 horses i've also never heard of in a 455... it should be at least 300 even if it's a smog motor, and at LEAST 375 ft.lbs of torque...and i'm being extremely ungenerous here.

Well first, it's obviously not the original motor. Clearly someone has bolted 70 heads onto a 73 block. The big drawback with that shortblock is the low-compression pistons. Olds varied compression ratio by changing the size of the dish in the piston. The heads all have about 80cc chambers. The original 73 pistons will have soup-bowl sized dishes. It's possible that the motor has been rebuilt once already with high compression pistons when the heads were swapped.

[Coltonis]

Thanks for the Replies! Well I'm hearing from you guys pretty much the same things my friend was telling me, this puts my nerves at ease. I definately think this one is a keeper now. However, One of my (possibly naive) goals/dreams is to get this car to pop a wheely. I'm not looking for a back-flip dragstrip type wheely, I just wanna get the front wheels jump off the ground a little when I punch it. Is it do-able? Keep in mind that I really have no intentions of racing this car... its gonna be my own personal import-eater! Would it be possible to do this simply by changing up the gearing and not modify so much on the engine? If I would need to beef up the engine a little more, without using $uper-dooper racing mods, what parts would you guys reccomend to upgrade? I've already been thinking headers and now (so long as some one didn't beat me to the puch) maybe higher compression pistons?

[Oldsguy]

With a 455 you already have quite a bit of torque and that is what gets you in the air, probably the easiest way is improvements to the drive line components and rear suspension. I think you would be spending too much money to do that with the car being mostly street though. I haven't had a car that could pop a wheelie or even lift the front a little. I know that Norm has one that can, you might ask him (88coupe). Good luck.

[joe_padavano]

Originally Posted by Coltonis

...One of my (possibly naive) goals/dreams is to get this car to pop a wheely. I'm not looking for a back-flip dragstrip type wheely, I just wanna get the front wheels jump off the ground a little when I punch it. Is it do-able? Keep in mind that I really have no intentions of racing this car...

You're right - that's naive. First, a big block A-body is a heavy car, especially on the nose. Second, you'll need significant engine mods, a beefed trans, a drag-race suspension and gears, and slicks to even come close to pulling a front wheel. Doing all this will have turned the car into a serious track car with limited street-ability. Finally, all that energy used to lift the front end is energy NOT accelerating the car forward.

[Oldsguy]

Good point about the weight distribution Joe, I forgot about that.

[Coltonis]

hmmm... well then, wheely-dream=bummer. Got it. I wouldn't want to turn it into race car. But minus the wheely stipulation what sort of engine mods would you guys recomend? My friend suggested I get an engine rebuild kit, are they worth it? The master rebuild kits all seem to run about $600+ but i think those come with new parts aswell (roller rockers, pistons,cam). I've seen some for like 100-200 but i think those are just gaskets? I'm not sure whats good and whats not for Olds engines, is there any secret recipe? (My friend is more familiar with Chevy engines)

[Oldsguy]

You might be able to get by with just head work and replacing the timing chain and some gaskets but for the extra money I recommend doing it all the way, I did on the last 455 I built. $600 is just the parts, remember machinist rates aren't cheap. But you usually get what you pay for, in this case, I think it is worth it.