Thread: Noob wants to know, what he bought

If the transmission pan is square with a corner notched out its a th350 if it's square without the corner notched out it's a th400. If your motor is a 400 then you have a good 400 small block chevy.

Post some pics up. The trans am came with the 400 bbc but there were other cars that came with a 400 sbc

Originally Posted by dsmuts

If the transmission pan is square with a corner notched out its a th350 if it's square without the corner notched out it's a th400. If your motor is a 400 then you have a good 400 small block chevy.

back then, Pontiac , olds, Chevy, Cadillac they all made there own engine, theres nothing interchangeable between the 4 engines, at all.


and being that it does have th350 trans, i bet its a 350 engine or smaller.

GTO Engine Codes! heres a link to where to find the engine codes and cui displacement.

if you stand at the front bumper, then look where the head meets the block, (pass side of engine) on the block will be a stamp, it will say 350, 400, or something lower, and the engine code should also be there. its also stamped on the block under cylinder 8.

thats a pontiac engine, im 100% sure of that.

and pontiac, never made a big block anything. all the blocks are the same. a 301, to a 455 are the same block size, just bored out, and different cranks were used.

Thats a th400 trans. Not sure on the engine though looks to be pontiac.

the car in my avitar had the same set up, 70 formula 400 firebird. had a 400 YS code block, 350 hp from the factory. and a 400 trans.


pontiac has that crazy looking intake, it came in a high rise and a low rise style.

when i was a kid, i worked on more Pontiac's then anything else. all 70's. when cars were really cars lol my best friend back then had a 77 GP, seemed like we were pulling his engine and swapping it every month, car started out with a 301, ( i think his dad dropped that in there) and his dad kept finding and rebuilding bigger engines for him. last one was a 428 i think.

Your trans is a th400 I was thinking about the 700r4 when i said square trans pan.

Originally Posted by Noog

Ok, the gear box has the cut out...so this should be a TH350? About the engine, I found out, that the 69 GrandPrix was only available as 400, 428 and 455 chi. From this side, it should be the 400 cu

with out being able to run the vin# you'll need to look at the block. like i said, pass side on the block under the head, it will say 400 or 455 or what ever it is, and under it or next to it is a 2 or 3 letter code. ie: 400 YS....the code tells you what hp the engine was rated for and other engine specifics.

Welcome from the states

I am not sure about in 69 but in 77 Pontiac used Chevy and Oldsmobile motors. That may be something to look into as well.