kso what control arms are you running on that car?
Custom fabbed to use torsion bars but they are basically the same dimensions pivot-to-pivot as for a Mustang II. It was an evolution, fortunately happening mostly on paper before metal fab work was done. Started with all MII stuff and dimensions, then decided to use (adjustable) torsion bars instead of springs which also kept it kinda Mopar-ish but required the custom control arms w/ bar sockets, then found that with GM (G-body) spindles with the lower steering I could lower the steering rack to fit under the oil pan better which actually made the GM spindles preferable to MII, then upper a-arms with inner pivots where they wind up wouldn't package w/ a Hemi in this case so I went to 3rd-gen Camaro (shhhh...) sorta-McPherson-strut style (which integrate shock absorbers but not springs), which conveniently for the stage I was at are the same below the spindle line as the G or S-10 parts. With all that, how does it work and package? Great.
So I'd be a believer in using GM spindles w/ the MII suspension, with the changes necessary to the rack position and ball joint hardware.
Probably the upper-inner a-arm pivots would work as-is with the G-body spindle being only a little taller then the MII, or at-least it'd be close. Generally w/ a front suspension you can use taller spindles (ball-joint to ball-joint) than stock design if you don't over-do it, for example '70s F-body would be too tall to replace an MII with but G-body would be OK with some checking.
One more thing to look at: Steering arm length, i.e. tie-rod pivot distance our from steering c/l. If the GM's are longer it will slow your steering down a little bit which wouldn't be that big of a deal. That I don't recall what the or any difference was.
