the reason for the 40 series I've been told is "the track is just demolished because for a long time all they ran was a big block MT" and the tire of choice was mulchers and they did just that turned the track to crap and the line around the track is heavily rutted and the people that run standard size wheels say they run into alot of broken parts by catching said ruts. thats just the general consensus at the track. I dont know if its right though maybe the standard wheel drivers are just hacks? and thanks for the info on the diffs I had just been told on 3 or 4 different websites that the LSDs performed like that. I havent gotten myself a TR yet Im waiting for a little more money and im going to do the trade in and get it directly from CEN and I've already planned on getting new servos and the aluminum servo saver arm and putting rear hinge pins in the front links. I unlike alot of people actually do a lot of homework before deciding on a kit but thats just the way I am. But I saw recently that CEN changed over to a SH .28 does anyone have the updated kit? I was also wondering why they changed the motor out I had heard nothing but good about the CEN .28 except for 2 people thats exploded theirs but whatever