I race and bash the AE 4.6, slapped a LRP .28 in, and it is too fast and durable for it's own good. Ripped the center out of the spur gear, melted the center, and proceeded to rip all the teeth off of it.
Get the FOC, new steering servo, and you are set.
I got a JP-4 with a side-pipe, removed the left dirt guard, got a set of Bow-Ties, and was set to race.