RE: OFFICIAL HPI RUSH / EVO THREAD
well, whatever you do with that, you need to get engine mounts first. you could spend all your money on those if you got the good ones, or spend 2 or 3£ on the cheaper ones. the rush is already geared pretty low (13/56), so about the only thing you could do is get an 11t CB, unless you can find any larger spurs than 56t. with the engine mounts you have to adjust your mesh properly so read up on that before you dive in