I did not mean that you should not use discs, only that the caliper does not determine the heat capacity of the brake, the rotor does for the most part. If the drums are not doing it for you, for sure, switch to discs. I put discs on my '62 K10 and they are great. I was able to swap from a '72 K10, they are easily 3x the brakes as far as heat goes. When a disc heats up it expands toward the caliper, not away from the shoes as a drum does.

Mac :{)

1962 K10 short step side, much modified for rally
1969 T50 fire truck, almost nos, needs a few things