[Formulabruce]

Originally Posted by 3tas4me

Yes, I get that, but isn’t the part number assigned by GM? It doesn’t make sense for GM to assign two different part numbers for the same part.

Today it would be for tracking costs, back then they were more worried about running out from one manufacturer. They kept track of which supplier was reliable. So yeah they are GM numbers. Another one that can be confusing is Jacks and Jack bases. Gm sourced at least 3 makers for that need, although there are differences.