THX Fredo the only rear exhaust 15 I have is an irvine do not think to many out there started life as a glow and you can see the top of head was machined down from a car head
guess Irvines try in the car thing , and evolved into this fitted with a diesel head by A.J. Coholic . I have not really played with it yet martin

they made up a custom prop nut/spinner since shaft as stock too short to mount a prop