If you have access to a set of accurate scales, check each rod/piston assy. Record the lowest weight and remove metal from conn rod cap on the heavier ones until they are the same. Does your crank need turning? have it checked. You might get by with polishing the crank and run .002" bearings.
I'v read that you don't want to turn the Vette's Crank. I believe the reason was that the journal surfaces were specially treated or hardened, and you would lose that . I believe I read that here in the Technical section on rebuilding a block. you might want to check into it. jim