Great stuff thanks for the info.[sm=49_49.gif] Just today I was working on the carb of the GP 42 to help with flow transition into and out of the throat. I did notice one thing, the barrel opening doesn't match the throat opening very well at all. I was considering getting a used barrel if I could find one and matching the opening by slightly bell mouthing the barrel opening to avoid turbulence. I do not believe this would negatively affect the signal strength. But I think it would help flow greatly.