How can you tell if a crank has been truned? My old main barrings have some numbers stamed on them-GMM400-A550B 4-325u7 My rod barrings have these numbers-GMM400-A54198-33187 The motor is a 327 out of a 1968 Chevy C-10 pick up. Is there anything on the crank itself. What are some things to look for. Thanks John.