I haven't played with tuning sha slide cutaway, I know they can work, but I cant help you there. Im more of a bing guy. Back to the matter at hand, when you say mid throttle is it more pronounced when its loaded up and you're accelerating at half throttle or is it when you're ripping and then back off the throttle while your still up in the revs. You got the type 2 shim/o ring combo? Nice, that should clean up the leak.