I'm fairly sure that they use the rotors and calipers from a mid 70's to early 80's 4X4. The brake pads should be the same for the 4X and regular 2 WD 1/2 ton trucks of that era.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine