I was running a Carter 6270 (opened up to 3/8" ) on my 408 equipped with a Pro Systems Pro Series 4150 Holley. The pump was always on the ragged edge of overfilling the fuel bowls and causing the carb to run rich and occassionally flood. The pressure on the Carter 6270 can get high enough (6.9 to 8.1 psi) to require a regulator. I did not want to run a regulator so I bought an Edelbrock Performer RPM Street Fuel Pumps 1720. The 1720 already has 3/8 inlet/outlet, runs at 6 psi and is rated to 600 hp. My 408 has performed much better since I made the switch. Here's the link the pump I bought: http://www.summitracing.com/parts/edl-1720/overview/make/dodge/model/dart
