Fuel system plumbing, advice needed....

[John S]

I'm in the middle of installing a new fuel delivery system. I'm removing the FAST EFI and installing a Holley carb on my 427 SBC. At the advice of a trusted local speed shop I left the A1000 fuel pump installed and installed the carb version of the a1000 bypass regulator. I can not get the regulator to adjust lower than 7.5 PSI and the carb is flooding out through the vent tubes and filling the manifold with raw gas.



Today I bought a new Holley "Blue" pump and dead head regulator. My question is what size line to I need to run from the pump to the regulator. I have 1/2" tubing running from the pump forward then connect to -8 lines to the regulator and -6 from the regulator to the carb.

Unfortunately I do not have all the hose and fittings I need to complete the installation and will need to make a parts run before the local shop closes.
I'm making just over 500hp at the wheels, will I be ok running -6 line from the 1/2" tubing forward or should I go with -8.
I've3 got about 2 hours before the shop closes till Monday, Thanks!

[John S]

I took a break from working on the car and read through the carb posts. I believe I have enough information to head to the shop and buy only what I need to get it to work well

[fast98]

I am assuming the reason you couldn't get below 7.5psi is that you need a -8 return for the a1000. What size was your return line?

[Schwartz Performance]

What he said ^

You can use a 3/8 or -6 for the Holley setup.

-Dale