Fuel line size

[SSHAKERR]

Hey, my 440-6 has a standard duty 5/16" fuel pump (normal for a 440 4bbl) I want to change to a better mechanical pump for street duty, like say a "Carter Street Super mechanical pump - 120gph, 6-7.5psi($66.95) " And I will need to upgrade my triple carb fuel lines to propper 3/8" - which I think is kind of wierd cause thats all that I see sold. Yet mine is 5/16". What effect would gas starvation due to under sized fuel line have? Top end loss of power? The only fuel problems I encounter are at the bottom end which I assume is the center carb accelerator pump.. Any advice on fuel pump is appreciated.

[John Kunkel]

All of the lines between the fuel pump and the 6-pack carbs are originally 5/16", the only 3/8" line is between the tank and the fuel pump.

[rumblefish360]

3/8 line end to end will avoid almost all street bound cars fuel starvation problems. A Carter fuel pump will take car of most mild HI-PO engines,
It so far had been enuff to feed my old 450 HP 360 passed 6500 RPM without a problem.

Top end loss of power?

Yes sir, you are correct since if the engines demand out strips the pumps abilty to feed the engine, you'll drain the carbs bowl, run lean, then out of gas and for a short moment, stall without the gas until the pump fills the bowl back up enuff to run. Then you get a punch in the back when it springs to life again.

[SSHAKERR]

Ok, I see what happened. I read the description for the kit from summit. Says: [ DCC-4529264 Mopar Performance Six Pak Fuel Line Kits
Fuel Line, Steel, Mopar Six Pack, 3/8 in. NPT, Hose Barb Inlet, Kit] I assumed that ment 3/8" tubing. I dont know what that description means. I assure you there is no 3/8 in. NPT anywhere in the kit. I have a small steel fuel line connecting the brass block to the 5/16 hose. Maybe the kit comes with a 3/8 barbed x 1/4" NPT fitting to go from the brass tee to 3/8 hose. Just doesnt seem like 5/16" line would be big enough at full throttle. Wouldnt it be better with 3/8" to the center tee with 5/16" lines to each carb? I guess there is no 3/8" fuel line kit to be had. I guess I could piece one together, but do I really need to?

Also, do I need a fuel vapor seperator? It came on 440-6 and 426s to prevent vapor lock. That where my fuel filter is now.

[rumblefish360]

A custom fuel line set up would be a nice upgrade and probably easy for you to do. Just copy the OE stuff with larger lines and fuel T's from Mr. Gasket or someone.
I don't know if you'll NEED a fuel vapor seperator, but it could help. I think if the factory did it, they had a reason. It could prove to be a bennifit to you in your set up.