I have a good ZR2 8.5" disc brake rear for sale. It has the Auburn cone style posi, 30 spline axles, and 3.73 gears. Comes with alum. calipers and stock rotors. Gears are in good shape. This isn't the Gov-lok timebomb....the Auburn posi is a strong unit. Nice upgrade even for the old 28 spline 10 bolts. WMS to WMS is 63". That is just a shade wider than a GM A-body (62.5"). Easy to swap in with a ladder bar or 4 link setup. Still has the stock leaf perches on it now for those needing that for a different application. Located in Binghamton NY (13901). Price is $699/best.
Mike - I'm not sure on that. I believe that the center section would switch....don't know if the bolt spacing on the backing plate area is the same. I'd have to defer to Jim (monzaz) or Roger (oPh) on that one. If you have an A-body rear available to measure from, maybe I can compare to this one.
Hey man you still have this for sale and how much you asking and If you could give me a shipping quote I might be intersted.