Gearing, start with a 22t in the 2wd with the 7.5
&
21t for the 6.5 in the 4wd.
Don't forget that if you run in the 7.5t in the 2wd, you'll be moved from the 10.5t class to the modified call.
Soldering iron, something like this:
Some details here:
http://www.oople.com/forums/showthre...highlight=iron
MiCk B. :-)