I'm trying to run the fuel lines to my Holley mech. pump. There's a 3/8" line and a 1/4" line running to the old stock pump inlet side. Why two? Is one a fuel return line, if so what do I do with it now? There's only one inlet and one outlet on the new pump.

 

The bigger of the two lines is the feed line, the other is indeed a return line. You can just cap it off if your fuel pump is not setup for a return line. Did you switch from fuel injection over to carb?

 

No, it was the lg4 w/ the original q-jet. Its now a 355 with many mods that I'm still completing. It's a fresh engine w/ only 15k miles since the upgrade rebuild. The extra inches were nice, but still not enuff power.