1970 ss 454 vapor lock 3/8 return fuel issue?

[Jeffrey Aldrich]

I have a 1970 Monte Carlo SS 454. It's an original build sheet car, fully restored—except for the engine. It now has a beefed-up 454 that tends to vapor lock when idling in Florida heat and traffic for extended periods.

To help with this, I added a return line and a return-style fuel filter, which improved things somewhat. I was also advised to install a quality Holley fuel pump and regulator with a bypass. The issue is, no one mentioned that the bypass regulator requires a 3/8-inch return line, but my car only has a 1/4-inch return line running back to the tank.

So here’s my question:
Does anyone know where I can get a fuel tank sending unit with a 3/8-inch return line that fits a 1970 Monte Carlo SS tank?
Or alternatively, can I safely use one of the existing fuel tank vent lines as a return?

Any advice or ideas would be greatly appreciated.

[DragCat]

Probably won't help you but ........

My 70 SS had the 3 port mechanical fuel pump. No issues in So Fl. When I did the crate swap the crate had a 2 port mechanical, so I just plugged the return line. Again no issues. 

Don't ask me about fuel mileage 🤣 Wasn't a priority 🤣