Ford 8 inch rearend swap

Just to add my experience. I have a Maverick rear end (5 bolt) in my 64 Valiant. It's been a couple of years IIRC. Charrlie's data is spot on. It fits like it was made for it. It's pretty basic for the possibilities it opens up. I believe it wasn't much more to get the Maverick rear, build it with new gears and get the bits and pieces required as it would have been to get the 7-1/4 rebuilt. You have to be careful with the mustangs as they changed over the years and some axle shafts taper. Can't remember details only that it was relevant at the time. :D
Oh, one more thing. There are two different size registers for the brake drum. (ask me how i know). May not mean much if the drum hole is larger than, but means a bunch when it's smaller than.