Is it only certain years of B bodies that don't need floor pan/cross member mods for a 518 install? I just picked up a good 518 out of a 90 ram and plan an install in my 67 Coronet someday. I thoIght I read that the early B bodies were tighter in the cross member area than later B bodies? Clearancing a floor pan is no big deal but I'd be happy not having to cut the torsion bar cross member