dual tank setup pictures

[MJN]

Anyone got pictures of the dual tank setup on a '74 truck? I'm having trouble with assembling the parts I have here, from a '78 and an '80 truck. I'm curious how the '74s were put together. Thanks

[sixty8chev]

I've got em on my 79, what exactly do you need pictures of?

[1FaastC10]

system is pretty simple really, take lines from both tanks, and hook them up to the output sides of the switch valve (hoses should be different sizes) and hook the engine side lines to the output of the valve, and wire it up.

[MJN]

I need to know which line goes on which fitting of the sending unit and where it is put on the valve also. I've got my drivers side sending unit with three fittings coming out of the top and my passenger side with two fittings out the top. On the passenger side, one is the breather and one is the output but whats the third one for on the drivers side then? I might end up getting all matching stuff out of the junkyard soon just to get it together right. Thanks

[plumbcut]

the 3/8" nipple is the "from tank" outlet.. the 5/16" nipple is vent and the 1/4" one is for fuel return used on some trucks. Sounds like you have two mismatched sending units.. Only a problem if your selector valve & fuel pump are designed with a fuel return. If not, just plug it on the one sending unit.
on the sending unit, obviously its the same thing, 3/8" feed, 5/16" vent, 1/4" return

pc

[1FaastC10]

the valves all have only 2 lines anyways, no vapor line through the valve, its just tee-d off.