I have rod bearings that have GM-45 18021941 195 A 62 stamped on them. What does this mean? Is it a std bearing? What size do I need for new rod bearings? As for the main bearings the front four have .0006 stamped on them and the fifth bearing with the rear main has .001 stamped on it. What size main bearings would I need?

 

Mic the crank.

GM didn't use "standard" bearings, the way we think of them. They machined the hard parts (block, crank, etc.) to their CRAPPY tolerances (but good enough for how they did things, since anything "better" would be muda), then selected soft parts (bearings) to fit.

Out here in The Real World, we don't do it that way. After all we don't have THOUSANDS of cranks and blocks and rods and whatnot, all falling out of their individually random production processes, every day, that we have to SOMEHOW assemble into functionable warrantable (even if only for 3000 miles) motors. We machine everything to a close tolerance, corresponding to "standard" increments of wear repair away from "stock" "nominal", and buy the soft parts that match. For some things (pistons for example) we machine the hard parts (block) to match the soft parts we have chosen.

All that GM factory crap is TOTALLY obsolete and beyond any possibility of matching.

Mic the crank. Buy bearings to fit. If it's too weird, get it machined.

 

That's brutal, but true. Looks like stock bearings, for a generic lo-po rebuild any standard bearings would probably work fine. Get some plasti-gage to rough check them. For a performance build, I'd take that crank to a machine shop for inspection and polish, get a recommendation from them. Money well spent.

 

Thanks guys.