I have a 1967 GTO 400. The engine identification number is located on the block, on the flat surface in the back of the engine where the distributor is. You may have to pull the distributor to read it. It is stamped....not casted.
There are various websites that will give you the breakdown that you are looking for. Just search Pontiac engine code identification or something similar. I'm guessing your car was built in Pontiac, Michigan.
I wouldn't go by the vin number. My car is actually a 1966 LeMans that was badged as a 326. Back then almost all Pontiac blocks (V8) were the same size in appearance The car had sat for 33 years when I found it. Apparently at one time back in the late sixties or early seventies a 1967 GTO 400 was put in. The only way I found this out was by using the numbers on the block by the distributor. Lucky break for me. I had a local engine shop rebuild it with a comp cam, flat top pistons and the rest is Edelbrock. Took me three years to build the car. Just finished it a couple of weeks ago.
Hope this helps.
Last edited by Trucknut; 01-16-2013 at 02:23 PM.