Yes they will. The emaxx 6 and 8 spyder diffs are nothing but Ofna Hyper 7/8/8.5 diffs. They were just rebadged by Robin and sold in UE's store. Remember to compensate with the spur/pinion combo since the Emaxx/UE diffs came from the buggies I mentioned earlier which are 43/13 while the CRT X2 uses 45/10 diff gears.
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)
You will love a truggy with full spider-diffs(thats the excact same thing), I have a full set in my Hyper ST Pro, and its just great and won't ever need a new diff.
TG
I have the cars that I really wanted before I got them ;-)
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)