"Note: There are two sets of holes in the frame for the crossmember bolts. The lower set of holes are for Powerglide and 4-speed transmissions, the upper set of holes are for 3-speed transmissions."
I think the above is correct, at least that is the way I thought it was.
Bob, I believe if you find the bolt hole information in the front of the assembly manual, it would be for the three speed manual as that was the base transmission. The power glide and 4 speed info would be in the back under "options". Again, I have a hard time remembering and my book is at home on the shelf in the garage.