Since I am going to swap discs into the rear using 76-79 F250 front 4x4 brakes (with big dual piston calipers). I had to find the correct bracket for the calipers. This pics shows front caliper brackets from a 1976/1977 ford 4X4 Dana 44 HD front end that measure 4 and 1/8" (left) and 78/79 brackets that measure 4 and 1/2" (right).
The only ones that will work are the earlier ones with a 4 and 1/8" radius otherwise the center hole is too big for the conversion.

Owner caption July 2005 · Photo 10 of 23