what kind of pump do you have, where is it mounted and what type/size of feel lines do you have? I have had good luck woth your plain ol Holly red pumps on moderatly modified cars. I mount the pump as close to the tank as possible so that it pushed instead of pulls. Some guys will say it doesnt matter and I have even seen poeple mount them in the engine compartment. Their wrong and I will leave it at that. I also never use the stock lines. I run -6 from tank to carb. If you think the pump and lines you have should be adequite, you might have a vacuum leak that is making it run lean or maybe you need to play with the carb jetting.