I've got a Castle Sidewinder with a 5700 motor (you would need a small pinion for the stampede!) that I'll sell for $100 shipped. Here's pics of it still installed in my XXX-T:
http://s92437987.onlinehome.us/ebayp...dewinder-1.jpg
http://s92437987.onlinehome.us/ebayp...dewinder-2.jpg
http://s92437987.onlinehome.us/ebayp...dewinder-3.jpg
http://s92437987.onlinehome.us/ebayp...m36-5700-1.jpg
http://s92437987.onlinehome.us/ebayp...m36-5700-2.jpg
System hasn't had much use. Installed in the XXX-T for oval racing and the class died.