I haven't had a chance to use either of the brushless Burns that I made, but wanted to at least mention that even with the motorisation and batteries I have in the Turbo Burns the BSW-1 and BSW-2 setup isn't necessary. You can stick to the standard BS-14 gears and as long as they are in good condition, well greased and
properly shimmed they will be fine. This will save you a lot of money.
One things that does not work is oil in the standard Burns diffs, even with the paper gaskets from the later classic Inferno cars. They leak all over the place.