I was reading a document about different castings of GM blocks from the 80's. Maybe this is known info but I wasn't aware. According to this doc...
http://www.enginepartswarehouse.com/enginecatalog/GENERALMOTORS.PDF
the Buick, Pontiac, and Oldsmobile all had 25526109 castings from 84 to 87. Does this also mean that casting of block from any manufacturer is the same as an 86-87 GN block? Would this also mean they are all turbo blocks? I understood them to have a higher silicon content to handle higher temps. If this is a well known bit of info I apologize for cluttering this space.
http://www.enginepartswarehouse.com/enginecatalog/GENERALMOTORS.PDF
the Buick, Pontiac, and Oldsmobile all had 25526109 castings from 84 to 87. Does this also mean that casting of block from any manufacturer is the same as an 86-87 GN block? Would this also mean they are all turbo blocks? I understood them to have a higher silicon content to handle higher temps. If this is a well known bit of info I apologize for cluttering this space.