70 Challenger,,
Is there a way to "delete" the return line ??
I have a 3/8 line feeding the fuel pump from the tank,,,,and a smaller line running back to the tank...

This is a new tank,,,from Roseville for a car i am restoring,,,
I am running a mechanical pump on the car....
I already have the feed and return line and tank plumbed front to back,,,,

Is there a way to not use the return line ?
If not,,,what do i need to "plumb" the return line near the fuel pump ?
Trying to "clean" things up under the hood,,,and didn't realize the duel line issue until recently as the car is nearing completion..
FYI,,this is not a stock appearing application
thx,
Doug

That is not a return line, more than likely it is a vent line and you need to use it.

Thanks Challenger,,,,
I will need to figure out how this is "vented" as it runs near the fuel pump...
I am researching some old threads you had replied to on a similar topic,,,
I will post some more questions as i educate myself on the topic,,,lol,,
thx for your help !
Doug

The FSM, you do have one right, shows this.

If it terminates near the fuel pump, then it is a return line. The vent line terminates near the firewall and is 2 pieces, the vent line.

All you have to do is cap the return if you don't want to use it now. I sure would not remove it though, you might change your mind someday and could use A RETURN.

I use returns on both of my cars and they have mechANICAL FUEL PUMPS.

Thanks Challenger,,,
As you mentioned,,it is a return line ( and not a vent line )
Do you see any problem running a 3 nipple fuel filter,,,( 3/8 for the feed and 1/4 for the return ? )

As an aside,,,I still need to "vent" my tank,,,,,,,,,
I assume i can run a "vented cap" ? ( or do you have any other suggestions... )
I have already installed a flip top cap on the car,,,
The filler tube has no port, etc for a "vent"

( long story short,,,but the car is a california ,,Western Sport Special car,,and had all the emission stuff on it,,,,i removed it when the tank was changed,,,,,so.....i do have a second "tube" in the trunk,,,next to the filler tube,,,that has about 4-5 small fittings coming out of it,,,,,right now,,,it's just mounted in the trunk for looks and has no further function to the gas tank like it did originally )

Curious on your thoughts,,,thanks for your help
Doug

Your car is a 70 and the vent line may not run up front. I have never worked on a 70 and the vent line may be in the rear frame rail.

On a 70 the vent line goes up into the trunk then back down and into the frame rail, unless your car is coded for N95 then it would have a 5/16" vent line going to a 3-nipple breathe cap on the motor.

Why do you want to use a 3 nipple fuel filter if your just going to cap the return line?

Thanks everyone for the replies,,,,

I will just cap the return line if that would be ok,,, ( no reason to use the return line ??,,,benefits ? none ? )

Need help with how to vent the tank,,,, ( this is not the original tank,,and there are no extra ports on the tank to use....)

if the cap is vented,,,will that suffice ?
Right now it just has the flip top gas cap,,,,,

What a mess.

OK Doug let's see if we can help you.

For 1970 you can have between 1 to 3 fuel lines depending on application. They are:

Fuel line: 3/8" for 440 and HEMI, 5/16" for everything else.
Return line: 440 and HEMI only
Vapor line: California cars only!

The return line runs from the "fuel filter/separator" (mounted on the fuel pump) to the SENDER. The sender on a 440 / HEMI is different. To remove the return line from the circuit you need to not use the "fuel filter/separator" and have a sender with the fuel line only.

The vapor line runs from the 3 nipple breather to the vapor collector in your trunk. If you want to eliminate this line then just take it out and switch to a single nipple breather and let you carb bowl vent to air.

This all assumes you bought a non-CA gas tank.

Once you have done that you will need a vented cap and that might not work on your fill neck but i would need to look at that further

Hope this helps

Morty,,,,thanks for you reply.
I knew it was going to get messy lol...
I have a 3/8 fuel line ( 440 ) and the return line installed.
( no vapor line to deal with )
The sender i have in the tank has fitting for both the fuel feed line and return line,, ( can i cap that fitting on the sender for the return line ? )
I will need to figure out the cap or fill tube venting
thx for the help
Doug

Yes you can cap it at the sender as long no fuel is being sent there aka "fuel filter/separator"

You just need to look at how it is going to vent.

Let me go check my non-CA HEMI Challenger vs. my CA Challengers do I'll post some more info.

OK - just checked.

The 70 non-California filler neck is unique. It has a vent hose coming out the top of it the leads to where your vapor separator is located.

The return line and vapor line are not related. You just need to have a way to vent air in while sucking fuel out.

Thx Morty !!

No problem