Yes, going high steer will eliminate the steering issues and the need for the "controlling arm"
Yes on the newer box. Bracing the frame isnt bad, Trail gear makes a kit that makes is supper easy, good time to push the box forward, since your moving stuff and the steering shaft needs to be lengthened anyway.
IFS Steering Box Mount Kit
I would pull the sway bar off entirely.
Make sure your front drive shaft has enough slip that it doesnt fall out at full droop too, and that your brake lines (front and rear) can handle the new suspension height/travel.
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92 ExtraCab on 38s: built for go, not for show
88 4runner: Solid axle, doubler, fun stuff
IG: rattlewagon
Its all about the parts you break, and the friends you make.