[Cocacolakidd]

+1^ All Lower engine cradle - Lower Crank Girdles are machined with their respective blocks. So the machining tolerances are pretty much set and matched between the block and the girdle. There have been a couple that I know of that have swapped out these on rebuild, but the engine did not last long in both cases before they had to be pulled apart again. One of those were re-machined and used oversize bearings and it only lasted 6 mos. before another tear down. It's usually cheaper to find a matched pair of Block/Girdle and build those.

This same mating/machining also goes for the balance shaft covers where if they are lost or toast the block and them are scrap - like the block and girdles.