OldSub,
I did make templates from the 78 donor truck that located the idler arm and steering box. I did not however measure the angle of the upper or lower A-arm cross shafts relative to the horizontal of the frame. Eyeballing the 78, it looked like the part of the frame that the crossmember bolted to was horizontal, so I just bolted it to the bottom of the 53 frame. I have seen another AD truck with this conversion done that put a big notch in the frame to simulate the kick-up in the newer truck frame, and enable the truck's front end to sit lower. I took the dropped spindles and drop springs approach to lower the front, but may end up installing air bags if I can find a setup cheap enough.
