I'm getting ready to drop a new motor on a bare '72 4x4 frame, with original engine crossmember. It appears to me that the motor mount holes in the crossmember are about twice as big as the motor mount bolts???? Is there supposed to be some kind of bushing/shim/whatever to fill in the gap??? Or did GM design it that way and I just use a big ole washer so I can tighten the mounts down??? Thanks in advance for the replies, I don't want to screw this up!