At this point I'm thinking these tracks, for the tiger
http://www.matotoys.com/canada/produ...products_id=74
and a few sets of metal drive/idler wheels, for the tiger
http://www.matotoys.com/canada/produ...roducts_id=131

As for gearing I'm thinking 15-20mph, with the reduction of the tire being replaced by a drive wheel that has to rotate x amount of times to complete one full track rotation verying by track length. Stated something and yet said nothing!