1/2T frontend on 3/4T truck

[kcjones]

I'm hoping you guys can help with this, as it seems like my last stumbling block planning my next bit o' work. I have a 67 C20, want to affect a 3.5/5 drop, and 'convert' to 1/2T frontend, plan on doing so in this way:

-Swap rearend with 73-87 12bolt 6 lug, shave leaf perches, weld on new trailing arm pads, use adjustable panhard that connects to passenger side trailing arm pad, new drop springs (5"), drop shocks and shock relocation, and rear sway bar.

-install new front end kit, which includes master cyl, booster, 6 lug rotors/calipers, 1" drop spring, drop shocks, front sway bar, and (most importantly), 2.5 drop spindles/upper and lower ball joints, and new inner/outer tie rod ends.

My question is this: The ball joints, inner & outer tie rod ends, and spindles all come together in a kit that installs "73-87 style ball joints/rod ends" Here's the link. Will these new ball joints bolt/press into my existing 3/4T control arms? Or will I need to replace my lower control arms with 1/2T arms? Also, should I replace control arms shafts and bushings?

Thanks for any help you can provide, I know the expertise is here to save me 30 drives to the parts store and a long hair pulling experience.