The MAxamps website tellsthe 6000 mah. are 20C cells.
http://www.maxamps.com/products.php?cat=46
The HV is the 4400 system, so I am thinking of upgrading to either 4,5 or a sensorless system. But don´t know if it help me that much on a track.
Regarding diffs I have already mounted the rear buks from Hardcore, so i will stick with those, at least for a while. On diffs I am thinking maximizer cups with robinson gears, but then I need a diff case for that. Will the Integy do or are there anything better? UE maybe? Will it work with the maximizer cup?