crt.5 rear drive shaft problem

[RUSTED]

well , i was bored and started to play around with some diffs and i was able to fit the inferno diff and cups with the crt.5 spur in the motor mount for the crt.5 but it doesn't fit in the rc monster chassis which means ill have to relocate then servo or make my own chassis, ill try making my own chassis first , wat wheel base should i make it ???