I think I bought the WRONG Fuel Sending Unit.... NEED HELP ASAP!

[sixpack_sid]

 I just got back from the All Chrysler Nationals, and picked up a fuel tank and sending unit, along with some other parts from Vans Auto. I have a 68 Charger with a 440. I am putting a fuel vapor separator in it. When I took the tank out of the box, I noticed there is no hole for the vented filler tube I have. I tried doing some research and it looks like there should be 2 tubes coming off of the sending unit, a 5/16" and 1/4". My sending unit only has the 5/16" tube on it. I am running 2 lines to the fuel tank. Did they give me the wrong sending unit?? From what I understand, the 5/16 runs the fuel into the pump. then the vapor separator, then into the carb. Then off the vapor sep. there is another hose that comes off of it. Does that hose run back into the tank? When I replaced the fuel lines on the car - there were 2 lines-a 5/16 & 1/4. When I bought the car there was no fuel tank with it and the trunk floor was cut out so I don't even know where exactly the tank mounted. Please help ASAP so if I have the wrong sending unit I can run back to Carlisle tomorrow and return it.
Thanks!

[randr]

they do sell vented and non vented. i have no idea if you got the wrong one but its sounds like you did

[b5blue]

440 with vapor separator will have a 3/8 fuel pickup and a return line built in to the sending unit. 5/16 only is for small block. 

[maxwellwedge]

440 with vapor separator will have a 3/8 fuel pickup and a return line built in to the sending unit. 5/16 only is for small block.  

   But the 5/16" sender is for everything else not Hemi or 440 .....  383 (Which is a big block) and down

[sixpack_sid]

The lines were on the frame when I bought the car and the vin tag states it had a 383 from the factory. Do i need to change the lines or can I get an adapter for the sending unit?

[b5blue]

Mine was a 318 car, I added a 3/8 and used the other as a return line.   

[y3chargerrt]

If its a 383 car you won't have the 1/4 return line. That was a 440 and hemi thing. Sounds like they sold you the correct unit. You will have to change the lines to run the vapor seperator.

[sixpack_sid]

I went back to Carlisle today and got the fuel sending unit with the 2 lines and it's a 3/8 and 1/4 or 5/16 return line. Can I just use an adapter to go from a 5/16 to a 3/8 to go into the fuel sending unit and the vapor separator? Or do I need to replace the 5/16 line I put in a few months ago with a 3/8 line ?

[terrible one]

Wait . . . if you have 5/16ths line in the car right now why not just use the 5/16 sending unit?

[maxwellwedge]

I went back to Carlisle today and got the fuel sending unit with the 2 lines and it's a 3/8 and 1/4 or 5/16 return line. Can I just use an adapter to go from a 5/16 to a 3/8 to go into the fuel sending unit and the vapor separator? Or do I need to replace the 5/16 line I put in a few months ago with a 3/8 line ?

68-69 440 B-bodies had the following from the factory.

3/8" sender with the smaller return line for the vapor sep.

5/16" main fuel line - yes - there was a mismatch between the main line and sender - Chrysler used a 5/16" rubber hose to connect the 2 of them....it was forced over the sender outlet.

The smaller return line.

In 1970/71 the 440-6 (not sure about the 440-4bbl) got the 3/8" main line.

You can leave your 5/16" line (It is correct) and add the smaller return line or just get a new set of both with the 3/8" line for a little more flow. You will need to get the proper frame clips that accept the main and return line for a neat, factory style install.

[sixpack_sid]

If I leave the 5/16 line on, will it get vapor locked? I already ran the new lines and mounted the clips to the frame for a nice finish-like maxwellwedge said. I would like to leave the lines in, but I don't want any problems later. Need your 
Thanks!

[maxwellwedge]

If you already have the 5/16" line in and are running or already have run the return line - You have the same setup as factory the 68-69 440HP cars and the 69-1/2 six pack cars and are 100% good to go!

[sixpack_sid]

Thanks for the replies! I got the vapor separator hooked up and put a fuel filter in the line before it. Everything looks good! The fuel filter is running horizontally and not against the firewall. The filter is pretty tight, no play in it. Is that ok? Or should it flex to allow for the engine movement when the car is running??