An MZ65 or the Nasty Jack clone of it, not to be confused with the normal clones that have tiny LONG header pipes, is a good improvement on the Phantom. It's far from ideal as the port of the Phantom and header pipe diameter of the Phantom is bigger than the initial stage on both pipes. The stock exhaust pipe can be trimmed to match up to the mz65 at the second half of the header right before the chamber. It works surprisingly well.