[RC-Monster Mike]

The SM servo saver works perfectly with the g-maxx chassis. I haven't personally tried the Maximizer posi diffs, but I love there diff cups and use them in most of my Maxxes. Sounds like your building a sweet truck. Any center driveshaft kit built for a stock e-maxx should work fine in the regular length Gorilla chassis. The Ext. kit is a sweet addition to the truck. Think about it for a future project, maybe. It adds to the driveability and helps keep the front end down (especially with high powered brushless setups). Welcome to the Forum!