I am switching beds on my 1979 (4x4,) too much body work to make it perfect. I found a 1978 (2x4) bed that is perfect, both are dual tanks. Here is my delima. Are the filler hoses intercahangeable? The 1979 fuel tank metal pipes have a smaller openings than the 1978 on both tanks, it looks like a small spring loaded metal piece blocks the filler pipe on the 1979, the 1978 has a round larger holes with no restrictions. When filling the 1979 the gas pump nozel will fit into the smaller hole and push/collaspe the spring loaded metal piece. Both the 1979 and 1978 have the smaller filler tube(vent) on the left of the larger filler tube They look to be the same length shape and curve/ design, they look interchangeable, the rubber hoses look to be the same also, even though the 2x4 front tanks is metal and the 4x4 front tank is plastic.
Both beds are still on the trucks so I am only doing a visual caomparison. I guess my question is can I use the filler hoses from the 1978 or should I use the 1979 filler hoses on the 1978 bed and will they work since the 1978 is 2x4? Are 2x4 and 4x4 filler hoses the same? My locking gas caps from the 1979 fit the 1978 just fine. Both trucks were dual tanks with all the emmission stuff, tank vents and lines to charcol canisters. The 2x4 had canisters under the hood 2 of them, the 4x4 has them on the passenger side rail also 2 of them. Thanks for your help.

 

Anyone have any information on this

 

Please, paragraphs. I had a tough time reading the whole thing.

From what you described, I'm guessing you are talking about the gas nozzle restrictors. You may be too young to remember why we had nozzle restrictors. They were installed so only unleaded gas nozzles will fit. Regular leaded had larger nozzles thus the older one had the larger fill pipes.

Steel elbow and hoses may fit...but I am seeing different revisions for the hoses due to emissions equipment. What the differences are, I do not know.

 

Anyone with a 1979 and emmisions have the smaller filler pipes ?