What is the Thread size of Head fuel ports?

[jgaytan]

Hello,

I have a 1997 7.3L f250 and I currently have a mechanical fuel pump and was looking at replacing it with a regulated electronic fuel pump system. What is the size of the thread on the front and rear head fuel ports, is it 1/4" NPT?

Also why does everyone run flow through head regulated systems? Wouldn't have hot fuel returning to the tank which can lower the life of the fuel pump? Instead couldn't you have a -6AN hose tie the two fuel rails from the front of the motor and feed fuel from the back of the head? Wouldn't there be fuel circulation and equal pressure on both fuel rails if you tie both fuel rails together on the front? Also your pump would run cooler because you wouldn't have the need to regulate fuel pressure with fuel that has passed through the heads. Look at little map below, although it doesn't show it the regulator will return excess fuel to the fuel tank.


rear of motor---<---regulator---<----fuel pump--<----filter---<----fuel tank

[Jeff_Northon]

1/8" NPT on both ends of the heads.

[pipelayerjdh]

Keep us posted!