very sensitive brakes after power disc swap

[speed-racer]

I just swapped power disc brakes on my 68 using the following components for a 1972 c10 2wd....

rebuilt master cylinder: Cardone # 10-1511
rebuilt calipers
early classic brake lines
disc/drum prop. valve from 1972 parts truck
brake booster and related components from 1970 parts truck

All other parts were purchased new for a 72 or were pulled from the parts truck.

My problem is that the pedal only has about 3 inches of travel (still sits on the rubber stop when it comes back) and is VERY sensitive. It seems like it is more sensitive when you slowly apply the brakes......if you apply the quickly, they are somewhat sensitive but are driveable. The pedal is extremely easy to press and does not do much of anything for the first inch or so. I have adjusted the pushrod to master cylinder so that there is play, and can feel a slight bit of slack in the pedal. You can drive the truck if you concentrate on applying as little pressure as possible, but it is absolutely terrible. Please Help!!