My 72 402 has the feed and return line from the tank. I installed a fuel pump from that only has the feed in and feed out to carb. Can I cap the end of the return line where it comes out of the frame, or should I change the fuel pump (not preferrable)? I am not worried about originality at this point because the car has slightly veered off that course and I am not running the emission stuff up front. Are there any detrimental affects of not running the return? Also, I am running a 750 Holley, and the pump I bought was for a 69 or 70 because I thought I would avoid the emission stuff that way.

Thanks in advance
Chris

The two lines on your car, One is the fuel delivery line, The other one is a VENT line. I built a 70 SS 454 Sta. Wgn. a few years ago with the two line fuel pump.
To make it look like a REAL LS-5 car, I took a piece of old brake line about 6" long and attached it to the fuel pump with the stock rubber hose and shoved the 6" piece of brake line it was attached to into the frame......... Now when you look at the fuel lines on my Wagon it looks like a factory LS-5 fuel system.
Dont worry about the vent line, Stick a fuel pump on your car and go down the road.
P.S. My dead end vent line has been on the wagon since 2002 and it fools a lot of folks.
Bob:hurray:

If I am correct (I may not be) the return line from the fuel pump was intended to help prevent vapor lock in the fuel pump due to high under hood temps on cars with A/C or a high performance engine. The theory was that if a small amount of fuel was continuously returned to the tank the fuel pump would stay cooler. I have plugged a lot of those return lines and never had a problem, although up here in Canada we didn't have 100 degree temps either.

The two lines on your car, One is the fuel delivery line, The other one is a VENT line. I built a 70 SS 454 Sta. Wgn. a few years ago with the two line fuel pump.
To make it look like a REAL LS-5 car, I took a piece of old brake line about 6" long and attached it to the fuel pump with the stock rubber hose and shoved the 6" piece of brake line it was attached to into the frame......... Now when you look at the fuel lines on my Wagon it looks like a factory LS-5 fuel system.
Dont worry about the vent line, Stick a fuel pump on your car and go down the road.
P.S. My dead end vent line has been on the wagon since 2002 and it fools a lot of folks.
Bob:hurray:

I was told the 2nd line was a return line. Why would a vent line go all the way up front?

Return Line...
and I have also had problems on hot days after plugging the line.
I am in Florida and we DO HAVE near 100 deg days and lots of them!

I am in Northern IL. I am not sure how hard it is going to be changing the pump with it already in the car. Should Plug the line or change the pump?

Up to you man !
If it were me ... Living down here I would change it. Fuel pump is an easy swap. I guess you being able to exchange that pump would be another factor.
Good luck bro

I think I am going to change it. Thanks.