watch out for...
wear on the main drive gear, see my post above
put a little loctite on the screws that thread into the wing mounts
make sure the slipper is tight and only slips under high loads
dirt and stones collecting in the rear gearbox
if you run on dirt the standard bearings will become contaminated very easily especially the rear outdrive bearings, I've found dynamite red seal bearings to be much better
must haves...
its heavy so any lighter parts are good such as the carbon shock towers and one piece carbon top plate
you can use the plastic outdrives from the other MR4 cars providing you buy the locking diff rings and the different thrust washers and screw (youll have to cut down the right rear outdrive to clear the spur though and you'll need the mr4 front bulkhead assembly too)
2 deg rear hubs