derek the ttr st-1 can be converted to a monster truck the stock upper arms and lower arms allow a eight shock option along with the option of a two speed center dif [transmission] not sure if the twospeed locks the center diff or works along with it [to lazy to investagate] These parts are ttr options so it won't be a aftermarket hack job .just something else to think about when getting a st-1 That way if your local race track should allows the st-1 with the 2 speed to race against the Losi lst ,AE mgt DTX warhead and other mt's. ie: Monster truck that handles like a truggy :] something about that says one fast revo killer lol