Rack and pinion

From what I see....the challenge in the rear steer rack install it it needs to be where located where the drag link is...which could be do-able. It is the steering shaft angle / hook up combined with exhaust manifolds of any variety that would make even MacGyver walk away.

I ran into a guy at Mopars at the Red Barn more than a decade ago with a rear steer rack in a E body with even more room than our A bodys that wanted me to "fix" it for him. After a look-see...I politely declined.

I think a front steer rack is do-able with the OEM torsion bar suspension, but from my experience, you will spend more time and money making it work correctly than going with coil-overs. The first rack / pinion I did on my green Hemi Duster was the compact Pinto manual rack and torsion bars. To get the geometry even close, I utilized a drag link in the front and modified the lower ball joints /steering arms. Rube Goldberg would have been proud.