Hi,

I just recently bought a 1979 cutlass supreme brougham. I obviously know someone has swapped it from diesel to gas. But I am trying figure out what block it has. Have searched everywhere and can not find anything about block identifier. Here are the casting #'s.
7582GM57LD any help would be greatly appreciated

 

Id it definitely an Olds engine? Oil fill tube is a vertical pipe on RF of engine, distributor in the back?

 

Yes you are correct.

 

That is an Olds diesel block. If it is currently running as a gas engine, someone converted it. Back when the diesels were new, Joe Mondello sold a conversion kit that included a gas engine cam and some other parts. You supplied the heads, intake, carb, and distributor.