Someone here did the conversoin and I can't remember if it was an HPI NitroMT or MT2.
Regardless, the diffs go south in a hurry. The gears in the diffs aren't all that great unless HPI has changed how they make them. The spider gears are really small, there's only two of them and they appear to be cast vs cnc'd, so torque is not their friend.
You might just want to find a peppy 18 or perhaps throw a TRX3.3 in it. Plenty of revs and more torque than most small blocks, but not so much that you will be replacing diffs as frequently.
orite i no you can buy harderned steel ones, like an upgraded set but i dont no,
the reason i ask is i have a .26 hotbodies in mine, ran 4-5 tanks so far and no problem just wanted to know if n e 1 else has had problems
If you want to go bigger, get the OS 18cvr. Its got a lot more power than the stock without so much that you just tear everything up. All I've heard about bb conversions is that they're fun for a couple of minutes then it's back to the work table.