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.