Power Steering Upgrade in '68 C20

[MrDanB]

After reading several threads about PS upgrades here, I am getting ready to tackle this on my 68 C20. I went to pull a part and wrenched off a ps pump/brackets, hoses,pulleys and a steering gearbox off a 75 Chevy truck. I think I need to modify the front bumper bracket to allow for the longer box, I read about the refill procedure with adding to the pump, then start the rig and jack it up in the front and turn the wheels side to side, then refill to proper level. Here are the parts I'm sketchy about:

-Do I need to get any kind of adapter/coupler from the '75 rag joint to fit the 68 shaft?
-Do I need to change out the pitman arm? Idler? tie rod ends?
-Anything else to look for as I go?
I plan to run a sbc 400 out of a '77 Chevy van w/edelbrock intake and Holley 750 carb.

Any help will be much appreciated!
Thanks-DanB