The VIN for '67 and later Pontiacs is located on the passenger side of the timing chain. The timing chain cover is hiding it.Its stamped vertical in between the two timing cover bolt holes.
The date code is stamped by the distributor hole. It will be the typical 4 digit code.
The block casting code is just behind the #8 cylinder. This is probably the easiest and most recognizable number. So, check it first and see if youre on the right track. It will decipher the year and engine size.
Both the date code and block codes are raised digits and part of the mold. Whereas the VIN is a manual stamped code.The problem with any of the manual stamping is that youre relying on the factory worker to be having a good day that day.
Good times,
Ray