I have a 1974 Powerwagon with a drum brake d44 in the front. I have found a 1/2 ton 4x4 dodge truck with the d44 in the front with disks, but its not 8 lug. I was plannning on buying new rotors, but could I swap the disk brake bracket and calipers and keep everything else from the old truck? I guess my big question is the stud pattern on the knuckle the same?

As long as you get the parts from a 80-93 dana 44 8 lug truck, ball joints out, they should work.