Can anyone tell me if i need to change my stock two barrell mechanical fuel pump, to one for a rour barrel? On ocasion while driving @45 mph my 67 charger with a 318 and 4 barrel (Edelbrok AFB) starts running rough, as if no fuel. As i let up on the gas for a few seconds and coast, it seems to clear itself or refill and run fine there after. I also have a fuel pressure regulator before the carb. Could it be related to rubber fuel line cavitation? Any thoughts would be apprecated.