Here is the GRU I use on one truck. Can't beat the price and I've pulled a lot of weight on a pull sled with it. I currently run a stock can for a good all around speed and go to a 55 turn for crawling/heavy hauling.
http://www3.towerhobbies.com/cgi-bin...?&I=LXVLE9&P=7
This is the best photo I have with it mounted.
