[Anthony]

Scott, I'm no expert, but it does seem as if you are getting some flexion in the rotor, like you said during hard transition before braking, pushing the caliper pistons back into the caliper, leaving you with a low pedal due to increased clearence. Sounds like it would be either due to wheel bearing play or spindle deflection.

This is very simplistic, and I'm sure you do this, but you must set the wheel bearing preload without any brake pads installed. I was used to setting preload as I did on my other 60's cars with drum brakes, where I always set the preload with the wheel and brakes installed on the car. Last summer, while trying to align my cobra, I could never get consistant settings when I would recheck my toe/camber after setting them. I'd check the wheel stability and it always seemed as if the wheel bearings were a little loose, but when I'd spin the wheel and set the bearings, they seemed just right, not to over tighten them. After 2 or three times of this, I'd thought I'd take the pads out and check them. The wheel nut turned about an extra 1/2 turn, and this solved the problem. The brake pads, as installed, must have been applying some pressure to the rotor, giving me a false sense of proper wheel bearing clearence/preload.

Good luck.