i used the willwood kit for the 65 mustang. it was 3 years ago that i had ordered it. i cant remember if willwood didnt have a maverick application back then or not, but the differece is in the wheel bearings only. you just change the wheel bearings in the hub to what drum brake mavericks call for. now they offer a maverick kit so no need to do that now.
65-69 Mustang use the small wheel bearings. The 70 Mustang use the large wheel bearings. The larger wheel bearings run cooler by rotating slower at high speed