The hyper 7/8/8.5 diffs (pro or rtr) have all the same gearing, 43/13. I have a bunch of them which I used on all my trucks.
Castle Neu 1520 on 6S LiPo Powered Gmaxx (Nitro Killer)
Predator with OS .21TM
Supermaxx with Mach .26
Revo with OS .18TZ
Kyosho ST-RR Conversion
Ofna CR with Tekin ESC/Motor (2)