Nothing sacred about an oil pan. With it off measure from the pan mount rail on the block to the lowest point anything on the crank rotating assembly gets to---it's usually a connecting rod nut. You can cut the taper out of the pan bottom and raise it to that measurement if more clearence is needed. I don't see a problem with pan to rack clearence since the MII rack is mounted in front of the crossmember and the pan is thinnest at this point but pan bottom to top of crossmember, who knows? We have sliced and diced pans in every conceivable manner including welding in a tube to run a draglink right through the center of the pan on some old Ford shoebox applications.

Evan