69 4x4 questions. Lift and front conversion

[too much stuff]

Hey all, i have started my project (to be named later) and have a few questions. It is a 69 4x4 shortbox 1/2 ton. I am adding a 4" lift. front and rear springs. (no blocks). I am also converting the front to a 1976 to get the open axle joints and disc brakes. First question, i will need a dropped steering arm. Do i need a 1976 application? Next, do i need longer front brake lines? If so, is that also for a 1976 application? Are any dimensions different on the newer front end? I need the u-bolts for the lift, and want to make sure it will all go smoothly. Where would you recommend getting these parts from? Any opinions on what i am doing here?(good or bad) Thanks, Eric