Can't offer much specific advice on the front bar on a 3/4 ton, but I added a rear bar to my 54-1/2 ton from an 88-89 Camaro. The stock bar is 7/8" dia. and the IROC-Z bar is 1" diameter.
The Camaro bar (with clamp-on U-bolt mounts) was situated on the bottom of the diff, but I mounted mine on the top so I could use the stock control links. The distance between mount holes is 39" which allowed me to drill a 3/8" hole (one on each side) in the lower frame rail to tie in the control links. My truck has basically the stock suspension height.
Just a suggestion. I've used the swaybar setup from a 93-94 2wd Explorer on several other straight axle applications. This bar measures 34" between link holes. This is a relatively flat bar and will be the bar I use on my Chevy.
I've had to fabricate a mount bracket which tied in with the spring/axle mount plate on my other applications. I've got some pics in my album that show the mount configuration.
Incidently, the addition of front and rear swaybars on any older truck will enhance the control of body roll and I've noticed no ill effects on ride quality. I realize we aren't trying to build road racers, but I find little excuse for not optimizing our trucks suspension potential. Especially when it can be done for just a few bucks.
The beauty of using salvage-yard bars is that my total expenditure is normally less then $30. for both front and rear bars, mounts and control hardware. I hope this helps.
