Ooohh, this looks dang nice! Couldja take a vid of what the exhaust noise is like? I wanna hear what a 14:1 compression engine sounds like breathing through an expansion chamber like that one. EDIT: looked on the first page, found the walkaround with it sitting there idling. You've got it tuned too lean, the idle should be a burbly sound, not a raspy sound. Making it run richer wall also allow you to take more advantage of the expansion chamber, because more fuel will be present in the exhaust, so more will go back into the engine.
