hydro boost woes

[tumleweed]

This thing is driving me NUTs!!!!!!! i installed a 1995 computerized lt1 and 4l60E in my 1988 crew cab dually everything worked out reasonably well, i integrated the a/c,cruise control, air box from the donor car(1995 caprice P vin). my truck had a 6.2l, th 400 and 4.10 gears in a dana 70. i changed the gears to 3.55's, it's fun to drive now but the hydro boost is really puzzling me,i used the power steering pump from the car being that it was all mounted on the motor,when the power steering is cold the brake peddle won't come all the way back to the top and this make the brakes drag and brake lights stay on.i have bled the system numerous times,i ve changed pumps and tried shims in the pressure valve and now it throws the serpentine belt off if i stab the brake peddle when it's cold, the hydroboost was working fine before the swap. i can't actually get any answers on what pressure is needed from the power steering pump to make the hydro boost act right and what the difference in the pressure of the two pumps is? any help would be greatly appreciated. mike