There are 8 lug disk brake kits now. Have a friend who installed this kit on his GMC 3/4 ton and is very happy with the results. Kit is for 47-59 Chevy/GMC 3/4 and 1 ton models.

'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12
'52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.