Reply to "Headers"

Another thing you might consider is simply bolting 4V headers onto your 2V ports. This adds a big pipe to a small hole, which does not obstruct outward flow, but the small port creates a 'step' that impedes flow back inside the port. Backward flow is called 'reversion' and can reduce power noticably in a given engine. Shops build custom anti-reversion plates for 351-Cs that do exactly the same thing, to add power or torque to an engine, and you'll be getting most of this free. Worth a try, especially since you already have some type of 4V headers that came with the car.