original GM body shim finish
 

Does anyone have knowledge of what GM used on original body shims for a finish in the 60s and 70s? I always see restored cars using the silver zinc coated shims that are commonly avalable. Original shims appear to have a black or gray phosphate finish. Or do they get tarnished that way from age?

Re: original GM body shim finish
 

Phosphate IMO

Re: original GM body shim finish
 

Ron, I'm in the process of getting a LOT of fasteners and shims manganese phosphated......

In reality can you SEE any body shims in place ??

What are you doing for the misc upper control arm shims....not the THIN
one with tabs, but thicker ones that are shaped like a "U"