In order to use an IFS CV you have to clearance it, I found this out 13 years ago when I did the SAS on my rig. Also at the time there were no kits you bought everything piece by piece and the only shop that I knew that were doing them on the west coast was All-Pro and Marlins. I was in uncharted waters in Roseville, CA. I talked to A-P almost everyday as I did it. Jon suggested I clearance the CV or get an 79-85 CV. After I did that I still had a bind on full droop on the PS. Called Jon and the first thing he asked me was how long were my shackles. I told him 6" on center. He told me to drill them 4.5 on center, which is 1" longer then stock. I did that and never had a problem after that. It moved my pinion up 8-9 degrees and the caster is just about dead on stock specs.
P.S. You guys have cheap prices on parts to day, my first Hy-Steer ran almost $800.00 from, and it was the second kit he ever sold. I broke one of the arms at the Hammers and Marlin replaced them free with his six-stud billet arms that he no longer makes.