RCU Forums - mammoth/rc10gt

Regarding the Mammoth ST, I have one, you can first start by getting some Dadders chassis braces to reduce any chassis flex. Found at www.dadders.net for 64 bucks.
Another upgrade to consider for quality aluminum arms would be from Big Air Products in either the basher or racer version. Found at www.bigairproducts.com for 115 bucks shipped.
Then check at www.rcvisions.net for aluminum hinge pin retainers (110 for a whole set) and some other cool aluminum products that rly help out.
Next, I would get some upgrades from www.hobbypeople.net like the center diff (if you plan on racing in the truggy class) and some carbon fiber wouldn't hurt either. Also, you could get the rechargeable receiver hump pack for the receiver batts.
Ummmm... a new radio wouldn't hurt either and you can get a Spektrum DX3/DX2 (I have the DX3 and rly like it, especially for racing, but some ppl complain about lack of features.)
Finally, a new pipe like the Jammin JP-1 (can find it if you just search on Google)
Those are just some of the upgrades you can get, if you need anymore or you have questions about the ST I'll be happy to answer them. Consider registering on an account for xtm.globalhobby.com so you can talk on the XTM forums. Hope this helps and good luck!