I'm not sure I understand the question. I just order parts based on make and model and assume/hope the seller has the parts listed correctly. Most sellers don't use the original GM part numbers anyway.

If you need to know your original GM part numbers, someone will probably post a link to the GM master parts list shortly. I'm pretty sure I've seen somebody link to it on this site before.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)