Brake pedal sticking

[MASTERBrian]

Here's my setup:
1960 suburban
4" HD coils rear, 2-1/2" CCP front disc conversion with drop spindle, another 1-1/2"-1-3/4" torsion drop.
The master/booster are from a 1990 c1500 hanging on a captain fab bracket. Replaced every brake line and completely went through rest drums with all New hardware and added auto adjust. SSBS proportioning valve. I had to cut and thread the booster arm and then put a clevis style arm and rod on the brake pedal. That is also threaded and connects to booster arm with coupling nut.

The brakes seem well slated, good stopping and front and back seem to squat at same rate under braking. The problem is the pedal doesn't always return up, half the time I have to pull back up with foot. What causes this? Before initial drive on New brakes it returned fine. I added a spring, but still not great. I will add when I bought, she was doa, but had a very rigged up spring and brakes were original and trashed.

I read someone say they had to drill hole lower on pedal arm by 3/4-1". I thought with captain fab bracket that wouldn't be necessary, but when I looked the booster arm is up higher on the boot and not centered. Drilling the hole is obviously not an issue, just curious if that is in fact what to do before drilling into pedal arm. I'm guessing, just unhook and see where the clevis lands while arm centered in boot.

Any other ideas?

[PGSigns]

I have drilled mine. It does two things for you. It will better align the rod and it gives you a better pedal ratio. Did you put a new master cylinder in it?
Jimmy

[MASTERBrian]

Originally Posted by PGSigns

I have drilled mine. It does two things for you. It will better align the rod and it gives you a better pedal ratio. Did you put a new master cylinder in it?
Jimmy

Yes, New everything.