Cutting the shell is an option but will damage the fan if you roll, not sure about the nosram speedo's but with the novak GTB's people take the fan off and put it next to the ESC on the chassis. I personally dont run a fan with a 6.5 motor but its up to you.
I think 6.5 is equivelent to 11t brushed, feels about that anyway.
Sorry, cant help on the setup for that track. HTH anyway
__________________
Canon 40D (350D backup) - EF-S 18-55 - EF-S 17-85 - EF 100-300 - EF 50 - Canon 430 EX || Speedlite - Canon BG-E2N Grip
Adobe Photoshop CS4 Extended
AX-10 Crawler - Thats all I have left!!!