I had a horrible time making my front disc conversion with 1966 C10 rear drums work. I think the problem turned out to be that I didn’t use the locking tool for the combination valve while bleeding. Once I finally got the results of that oversight resolved the brakes now work perfectly. The effort is light, and the truck does stop more quickly if I brake more quickly. I had no interest in changing pedal height because it matches that of the clutch pedal.

1950 GMC 100 Panel Truck, 1958 270,
3-spd Saginaw with BW OD,
3.73 12 Bolt Differential from a 1966 C10,
Front Disc Brakes
Hill Holder
Bought it in pieces 9-1976, driving since 6-1978
Follow in the DITY