rear disc brakes on 8 3/4
This is the kit I bought on ebay.
Direct bolt on and badd *** stopping power.
http://www.ebay.com/itm/mopar-8-3-4...ash=item35af5fe3d4:g:JNgAAOSwnipWXf0a&vxp=mtr
Bruce
Yet another kit (and Right Stuff's kit is the same) with those junk 79-85 Olds Toronado rear calipers. If you do some research on those you'll find pretty much everyone has issues eventually with them adjusting correctly (which is a function of setting the parking brake on them), and sometimes getting a low pedal.
In addition they have significantly higher slide force due to the slide design since they are just the old school "metric" gm calipers in a general term. Why use stuff that wasn't that great 30 years ago?
The Mustang Cobra parts used in the Dr. Diff Kit are pretty much bulletproof by comparison. Unlikely to have issues of any kind with adjustment, have captured slide pins which is basically identical to what you'd find on a brand new car from today. They are also a much higher performing piece as you can get pretty much any pad you want for them.