Thanks all.
I have an 85 ext cab on 63 Chevy, with detroits in the rear and Aussies in the front, geared 4.88 on 33's BFG muds (old style). Front axle was recently rebuilt and upgraded to FJ60 vented rotors, v6 calipers and MC with larger 86+ style drum in in th back. Can't wait to take it out