Early..47-53 bell housing had "flat" mounts. Sort of true horizontal to the crossmember. 54 the mounts came to be angled tipped down to the center. Same time the V-8 is introduced(265). The company chose to make all the bellhousings and crossmembers fit. Out with the old..and in with the new. The truck had to wait for the steering to move for the wider V-8. But the crossmember was changed. A half step at a time I guess. Like the 55.1 and the 55.2 the truck got a mid year change(new chassis and new sheetmetal) Lots happened at that time. Then, the 285 comes right on top of the 265, same mounts in the early versions.

Steve H