[Pyrotechnic]

I agree, you should swap heads to some that flow better and have smaller combustion chambers.

Also as a note with the MSD Pro Billet distributors, they comes with the heaviest springs from the factory to give the slowest timing curve so those with detonation prone combo's don't destroy stuff. If you haven't already, you need to use the lighter springs that come with the kit to get a proper advance curve. One blue and one silver spring is what I used on mine.