heres what I'd do, what HP goal and what the goal for the car? The best performance is subjective. street machine, sleeper, drag racer etIc. If you're just wanting a sleeper/street machine, I'd go with the factory 4 barrel and adapter, run the carb you have. Take the extra 300, get a custom ground cam from Oregon cam grinders (150 bucks), and then see how much
@halifaxhops would charge to do a complete, tuned distributor for you like he did for mine. With the cam, carb, intake and correctly curved distributor, you'll be pushing near 275-300 hp
the intake difference alone between the factory 4 barrel and the windtunnel intakes is gonna be maybe 30-40 hp tops, and thats assuming you do the cam. The biggest areas that held the polys back in 4 barrel trim was the exhaust manifolds (very restrictive even for factory pieces) and the cam was very very mild.