I built my own brackets and used Rotors from a 2000 Chevy TopKick and Calipers from a 2015 F@&d F450. Tied that to a Hydro-booster and Dual Master Cylinder form a 1990 GM Motorhome. Used the the rear axle from the Motorhome as well, so 4 wheel disc brakes. Truck stops like NOW.
TUTS 59, was it a challenge with the set up you created to get the same width of the spindle/rotor/spacer assembly and overall WMS measure/ tire fit in fender as the original brake set up had? I would like to replicate your set up. It’s very hard to find P30 or c3500hd parts for Grigg’s setup.