Bought the 820 conversion kit from Kershaw. http://www.kershawdesigns.com/E-Revo...Conversion.htm The Dewalt motor is great. I bought two and put them on different Summits. I compared the 21t, 19,t and 16t pinion in side by side test. Forget the 21t, broke the rear drive axle in two minutes. The 19t accelerated faster but overall speed in comparsion to the 16t was about the same. both the 19 and 16 have incredible low end torque. I was crawling over stuff the stock Titan couldn't touch. I think I'm going to stick with the 16t or maybe try the 14t.
The conversion kit was a breeze, the instructions made it very easy. Dan at Kershaw was very knowledgeable, easy to deal and had lots of ideas. His conversion kit is so simple, even I could do it.