Summary

I remixed the original part from Kyle Hart (https://www.thingiverse.com/thing:4760341) as the holes were not perfectly lining with my Injora transfer case. I also included some hex provisions in the bottom so you can insert nuts (use a welding iron) before attaching the case to the bottom part of the chassis.
I also elected to install the steering servo on top of the front diff and thus modified the engine/gearbox fixture in order to get maximum travel of the front axle.
Note that the rear intermediate shaft of the transfer gearbox needs to be cut, you will also need to adjust the lenghts of upper and front arms to fit.
My next design will be a gearbox enclosure to close the gap between the dashboard and the center armrest.
Thanks to Surfdude1983 for the initial bulletproof upgrade (https://www.thingiverse.com/thing:4603082).
Enjoy !