disk brake conversion trouble

I recently installed a complete disk brake conversion kit purchased from CPP. The problem I am having is weak brakes and having to use excessive pedal pressure to apply brakes. The old drum brakes I took off worked better and had more stopping power. The kit included everything for 4 wheel conversion of my 65 c-10, including new master cylinder, booster, brake disks, calipers, hoses, lines, e-brake cable etc. The pedal is not at all spongy and I have bleed out all the air from system, I need some ideas of what I should look for that is causing my weak brakes.
I am looking forward to any Ideas.
THANKS!

good morning,

The proplem you are having is caused by not having the rear parking brake adjustment done on your calipers. Take a look at this guide to get the rears adjusted up:
http://www.classicperform.com/Instru...brakeguide.pdf

there is a section on just the rear adjustment.