I agree with brian6pack. When I first put my 340 in my dart with just a cam, intake, headers and carb with a mechanical pump, best it would run was 13.7@102, with 3800 stall and 4.10 rear. I tried jetting for MPH at the track but nothing would change, same et and MPH. I double checked everything, in the end I switched to a black Holley knock off pump and regulator, first run ran 12.90 @ 105 and jetting started to affect MPH. It already had 3/8 fuel line from the tank. It may not be the only thing that is off, but worth checking.
