get an os 18tm if you are using the ez start, get an os 18 tz if you are using a starter box. best motors and easy to tune. When I had one i bought a chassis for a 3.3 and switched it over to the longer wheel base and it made a huge difference. all you need is a chassis, body and a longer driveshaft. And a lot of time LOL. If you are racing it will be night and day.