SSBC disc brakes won't stop

AJ/FormS said
This sounds like a mechanical issue. As in bent pads or those pesky anti-squeal shims between the pads and pistons, or some kindof flex in the system,including but not limited to,the rubber flex-hoses, or pads not running flat to the rotors,or even the bracketry.

I had three Wilwood M/Cs available to me when I put the system together. Started off with a 7/8" and worked up to the 1 1/8" which gave the best pedal, and highest operating pressure. I get 1300lbs to the calipers, no booster.