Just to add a little extra, my '62 GMC 6500 had Air Brakes with the swinging pedal. That's the truck that had the steel pedal with no rubber pad and the word "Air Brake" on it. I am far from an expert as far as the mechanicals go, but that truck (as long as the brakes were adjusted correctly) always stopped just fine, empty or with a full load (32,000 GVW). I also had no trouble with controlling the amount of pressure with the swinging pedals, whether I applied pressure directly or when the heel of my foot was on the floor. My '67 GMC 7500 also had swinging pedals, altho that one had a rubber pad, and again no problems, but my '71 9500 did have the foot pedal and I have to say I did like that one better, but the difference was not enough to matter much, to me anyway.
The time I would have trouble with brakes were those IH 1600's and 1800's that had power hydraulic brakes. After driving the GMC all day and then jumping in an IH, I almost always left 4 rear wheel patches of rubber on the road. Those brakes were extemely touchy. I think those trucks would stop even if you breathed on the pedal.
Bill
