brake problems

[super1ton]

i did a axle swap on my 72 gmc 1/2, put dana 60 in the front and dana 70 in the rear. went to 3/4 ton booster and master cylinder. i can't get the rear brakes to work, tries putting 1/4 lines to each wheel cylinder and readjusting them, still nothing. they are drum brakes and everything is brand new. anyone have any idea's, i was told i might have to go with an adjustable prop. valve? any help would be much appreciated, i am on the verge of getting some dynamite to fix the problem.