The mount is designed to not have any metal to metal contact loaded. The generous gap specified before a load in applied ensures that there will be no metal to metal contact once the load is applied.
There is one other thing which ensures no metal to metal contact when you are done. It involves the instructions for tightening the nuts which go through the crossmember.
Tighten them just snug. They are referred to as locking nuts. Overtightening them will cause metal to metal contact.
The original bolts have a holes for a cotter pins.
These pins do not lock the nut in place. All they do is keep you from losing the nut once the rubber gets oil soaked and collapses and the whole works bounces around causing the nut to want to come off.

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission