Been fighting this breaking up and can't figure it out. It's reacting to changes in plug gap, fueling and timing. Some things make it worse. Some better. But it never pulls clean as soon as it breaks over into boost it acts up.. Iv been from 11-22* timing. Fueling from 11.0-12.0afr. Plug gap from .020-.028. Tried tr6 and br7ef plugs. Runs fine until it breaks over into boost. It's on 8lbs. Doesn't matter if its 2500 or 5500 rpms. Same breaking up.. Runs completely normal until it gets in boost. Ideas??