I took my crank to the machine shop for a polish. When the worker was examining the shaft he notice groves between the shafts where it suppose to be smooth and shiny. He statind i will need to grind the shaaft down to the next level. I already bought the standard size main and rod bearings for the engine im currently rebuilding and my question is can i use the same bearing i bought or will i have to down size them. If so, what size should i down size to?