hi i got a 400 small block from a friend he say it ways running when he took it out.The thing is we broke it down the crank looks ok but we do not know if its std. or 10/10 or 20/20 its looks like its the crank thats came in the motor years ago how can i tell if its a std. crank or not.The bearings just got gm 400 on them and an A200 0005 0s