Thanks guys.

The center diff is the stock one. I replaced the metal spur gear with a kyosho # IF148 spur gear (plastic). I got that info here off the forum THANKS for that tip.

I went with a 13t pinion seems to work great.
I ran it for awhile today and I was AMAZED at how fast it was and how well it handled.
I did end up breaking the rear A ARM hoder. The plastic part that attaches to the differential let go and the a arm pin came out. (5 min 6 dollar fix).

anyone need an emaxx :) no going to need it now :)..