1/4 " return line set up

[Denis Arseneau]

Getting reading to plumb all my fuel lines on my 73 Roadrunner. Automatic with a 440. Right now the engine has a square bore intake manifold and a buddy of mine has loaned me his 750 holley to get it going for now. According to the service manual, two return lines start at the carb then canister and back to the tank via the vapor liquid separator. Do I need to use the original Thermo-quad or is there a way with the holley

 

[72RoadrunnerGTX]

The pictured lines are the fuel tank vapor recovery system, nothing to do with fuel return. The fuel tank vapor separator to charcoal canister hard line is 5/16” not ¼”. Aftermarket carbs will not have enclosed bowl vent vales nipples or a dedicated canister purge port the OE carbs have. The “carb” port on the canister can be capped off. Purge port on the canister can be “tee’d” into the PCV line with a small restriction to have some purge function with aftermarket carbs.

440 HPs in ’73 did have a ¼” fuel return that ran from the fuel pump mounted vapor separator/filter back to a 3/8” fuel tank sending unit with a ¼” return nipple.
Refer to the fuel pump section of the FSM

 

[Denis Arseneau]

Thanks 72Roadrunner GTX. Found a couple of dealers that sell the vapor separator/ fuel filter. Does this item replace the common inline filter and I'm assuming that it goes between the fuel pump and carb. Not sure where it bolts on the inner fender or frame rail.

 

[72RoadrunnerGTX]

Bolts to the motor, bracket goes under the fuel pump bolts. Yes, the originals contained a screen, replacing an in-line fuel filter.

 

[Denis Arseneau]

Well it's true that a picture is worth a thousand word. You da best.