i did some parts swapping to a 3908. because i bought a roller. already this is faster with a new charger for my batts. and all the lighter parts on this truck. but check out my link here. http://traxxas.com/forums/showthread...64#post5250064
see if you guys can help out too. i have read something about this before. but i also want to post more pics later when i get some time.