I will be running a center diff in my maxx w/ the FLM chassis. I am waiting on a custom mount from Mike which will mount the motor above the center diff. To my knowledge there is no kit for a conversion. To have it done right i would contact Mike and have him make you one..good luck

Here's one Mike made for another customer which will look like the one he will be making me.
http://www.rc-monster.com/forum/showthread.php?t=10233
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S