I have a friend who has the volcano epx. He has added the best Novac brushless motor and ESC to his volcano..
Is he very inventive? He could sell the brushless system and then convert the Volcano into a crawler. I reckon it wouldn't be too much work to flip the diffs + casing upside down and mount them under
the chassis to give heaps of ground clearance. Then cut holes along the chassis so the shafts from the transmission go down through the chassis. You'll need longer driveshafts than stock though. This is pretty much the arrangement of all 1/8th "trucks" - the Volcano really is closer to a truggy than a truck in that respect. In fact he could keep the brushless too.
A friend crashed his Volcano and I offered to buy it off him and this is the mod I would have attempted - but then he gave it to someone else