Fuel line routing

[1979C20]

I desperately need a routing diagram for fuel lines on a dual tank 79 c20. It has no return lines, and cNe stock with 2 smog canisters and all the smog goodies, california truck. I have a fuel leak from the top of the passenger side frame rail above the selector valve. I want to drop both gas tanks and replace all of the rubber fuel line so I dont have to deal with this anymore.

[Blazin]

If your just replacing the rubber just pull the tanks, and replace the rubber. Not sure what the fuel line diagram is going to do??
You can also do this by removing the bed.

[bake74]

     I am with blazin, if you are only doing the rubber lines, it should be easy enough to do one at a time.  Blazin is 100% correct, it is way easier to do if you remove the bed, instead of dropping both fuel tanks.

[Irish_Alley]

with two tanks prob be easier to pull the bed

[1979C20]

Yeah, but I dont have the time, man power, ir storage to remove the bed. I can pull the tanks out by myself with a floor jack and a ratchet in ten minutes. I was hoping for a diagram because I need to know how much hose I need and I need to make sure my hoses are hooked up right.

[Blazin]

Pretty sure there is only one way to hook them up. 5/16 hose won't go onto 3/8 tube very well, and 3/8 hose will be sloppy on 5/16 tube.

[1979C20]

So far, all I have seen is 3/8ths.

[Blazin]

posibly could be the same size I guess. Mark them with two different color paint pens?

[1979C20]

See, this is why I would like the diagram. No guessing. The PO had spliced the to pump and the from dticer tank lines together and took the splitter out of the loop. The pass tank, the gauge would swing all the way to over full, and the wire to the splitter wasnt connecting. So I fixed the wiring and plumbed the splitter back in, and im not sure if the hoses are right.

[Irish_Alley]

cross over line can be 5/16 or 3/8
vapor line is 5/16
fuel is 3/8

this is the best i can help out with

[1979C20]

I dont have a return line, my driver side vapor line runs on the outside of the driver frame rail, is the crossover line the one that goes from the driver tank to the switcher on the passenger side? And I found my leak. I believe the switching valve is either getting weak or the oring is leaking, because after I shut my truck off, it startes leaking from the supply hose from the passenger tank, above the pass frame rail. There a hole in the hose. But, that tank should be empty. Which means the switching valve is leaking the fuel from the other 2 lines, into the passenger line where it leaks out. So, I switched tanks before I shut my truck off and it stopped the leak. But I noticed a few spots if hose that are splitting, so i still need to replace it.

[Irish_Alley]

The pic is a universal one and yes on the crossover

[1979C20]

I have one more question, what size hose is used on the sending units? The output and the vent. Thanks in advanced and thanks Irish for the diagram, its helpful.

[DnStClr]

The hose size will be the same as the tubing size. The main feed is 3/8" and the vent is5/16". If you had a return line it would be 1/4". 
Here's a pretty good site for some more info on fuel lines and sending units etc.
http://www.inlinetube.com/Sending%20Units/gas%20sending%20units.htm

[1979C20]

Is it possible to unbolt and slide the bed backwards on the frame instead of removing it?