I suppose you could have the crank drilled while it's out, for sure. I don't know what the machine bill would be. I should have recorded the measurement. If I don't write stuff down, CRS hits immediately! I do think it was right around one inch, if using stock bell housing. I guess the reasoning for cutting the input was, simply, hitting the easy button. It can still be used behind any thing else, as long as you use the magnum roller input bearing. One of the conversions I did, the trans came from behind a cast crank 440 that hadn't been drilled. Measurement was dead on from 440 to hemi.