This is my car has about 700 miles on a frame off, 312, 5 speed, the problem is the new / rebuilt fuel pumps put out to much pressure (9lbs), here's how I solved it, I replaced the pump with a 6 valve fuel pump for a marine FE Ford, I then hooked a vacuum line from the back side of the diaphragm to the constant vacuum port on the carburetor, the vacuum lowers the fuel pressure to 6lbs at idle, when the vacuum goes away the pressure go back up.