Man what did I do, 350 or 455

[Fugitive77]

Ok got a 1977 442. Build sheet says 350 350 trans. I ponder over new engine and trans options. Decide to go with 72 sbo and a 200r4. New Motor at the machine shop so I start looking at the the old motor. It's black with oil, not much to look at, then not familiar with 455, I discover that the GM blue is not there,but what is there is med metallic blue. Wait, isn't a 455 that color,what the hell is under my hood? Intake is black with crud, rub it, it's metallic blue. Got late, went home. Is a stock manifold marked 455? Besides being dirty, hoses all over the place, what else to verify motor size?

[oldsmobiledave]

rookie tip...look at the heads

...if it is a # it is a small block & if it is a letter it is a BBO. Ofcourse you can make SBO heads work on a big block & vice versa but this is hightly unlikely in this case.

don't get hung up on the paint color....I can rattle can an engine any color you like & that does not make it a big block.

[djb56]

The block # just behind the water pump will tell you. Write down the # then go on line to find out.

[Fugitive77]

Thanks guys, talked to Dennis this morning it's a small block. Man, it was late and it really rattle me. It's been thirty years since my last Olds. One thing about a big block Chevrolet, you know what ya got.

[Cutlassefi]

Thanks guys, talked to Dennis this morning it's a small block. Man, it was late and it really rattle me. It's been thirty years since my last Olds. One thing about a big block Chevrolet, you know what ya got.

Not necessarily, the numbers are in the back and it could be a 366, 396, 402, 427, or 454.
Olds are easy, Pontiacs are even easier to tell, it's cast into the block.

[Fugitive77]

Basic stuff like small block and big block Chevy. That stuff is a no brainer, displacement well... An Olds, if you don't know your stuff, they can all look alike, valve covers are all similar.

[Cutlassefi]

Same can be said for a SBC or BBC, all pre 87 SBC's are the same and so are post '63 BBC's. I guess I don't get your point.

[ragz442]

Same can be said for a SBC or BBC, all pre 87 SBC's are the same and so are post '63 BBC's. I guess I don't get your point.

I get his point, when you pop the hood on a Chevy, you know it's a big block or small block right off the bat, I don't think he was talking about displacement. Pontiac's didn't have a big block, all the V/8 block castings are the same size externally.

[75ga]

Kind of on the same topic, how do I know if I have a 455 or 350 Olds motor? It's in a '75 Cutlass, blue motor.

[Hurstolds1973]

Big blocks have Letters (J,C,D,G,KA....)on the front drivers side of head sbo is numbers(8or......).

[75ga]

Okay, thank's. Mine has a "J" stamped on the driver's side. What do the letter's refer too? The motor was replaced at one time as it had a 350 new. Previous owner told me it was a 455, just wanted to know how to confirm.

[75ga]

Dumb question, a "J" is a 455 then?

[mdkingsley]

It is the head casting letter but it is the easiest way to see if you have a big block. All 73-76 came with J except I have heard the 73 hot 442s came with KA heads. Gary C. can feel free to coment on that he would know better than me.

[zates]

Dumb question, a "J" is a 455 then?

There are no "dumb questions" bro. If there are, I've already asked them! :) One of the great things about this site, is nobody judges. Everyone's super-helpful.