Need 4x4 steering box and assorted parts for 75 F100 4x4

[mofoco1]

Just got my son a 75 4x4 f100 has a 390 and np435.It has strongarm steering and i need to get power steering for him. Let me know what you have and what you need, must be able to ship to 93612. Not sure if it matters but the stock box is mounted on the outside of the frame. The truck has a hi pinion also with drums. Thanks...Mo