I have a 272 in my 55 Fairlane Victoria that I recently changed from a 2 barrel carb to a 500 cfm 4 barrel from Edelbrock. The car idles great and seems to run ok at slow speeds but is very non responsive if you give it any gas. It bogs down when you put any load on it. I have checked all the fuel lines for blockage, adjusted the timing back and forth, adjusted the idle screws and nothing seems to fix it. Any ideas what the problem could be? The car is stock but was rebuilt a couple of years ago before I obtained it. The data code on the car says it came from the factory with a 4 barrel but somewhere along the line someone converted it to a 2 barrel. I put a correct 4 barrel manifold from a 56.