I don't think so, sorry. The M3 series has a larger body diameter where the head attatches, won't work. Get a 9P body and tailcap from lighthound, that would make a great 3-cell KL3 combo and runtime would be da bomb.
not that I know of...besides it would be a little difficult to go from a bigger body to a smaller head. Nothing is impossible but the machining cost would be pretty high. Just imagine mounting a 12-inch tire on a 30-inch truck wheel.