[396mac396]

I have a 72 Lemans GT with a 350 2bbl carb and no a/c. I"m installing a 72 400 4bbl engine. I don't have a vent line going back to the gas tank like original 4bbl and a/c cars have. Is the vent line needed to prevent vapor lock? I have the ECS set up on my car, could I use the 5/16's vapor line on the pass. side of frame as a fuel pump vent return and vapor return at the same time, or would I have to disable the ECS to use as only a fuel return. Which fuel pump should I use long /short bowl 2 or 3 lines, thanks.

[400 Lemans]

My car is a factory 400 without AC. It came with no return line back to tank. I'm sure the return line system works better but they didn't consider it necessary without AC, i guess. I have never experienced vapor lock at all on mine and its got just a short bowl 2 line factory fuel pump.

[396mac396]

Thanks, maybe it's an A/C requirement. Does your car have a 2 or 4 bbl carb?

[400 Lemans]

It was originally a factory 2 barrel 400 but since changed to 16 big valve heads and 4 barrel.Not sure if the non AC factory 4 barrel 400 cars had 2 or 3 line fuel pumps. Maybe someone else will chime in.

[indymanjoe]

400 2bbl with A/C came with the 3 hose fuel pump. My 72 Luxury Lemans BTW