Sending unit and tank questions.....

[74Chevy74]

I'm in the process of prepping for the longbed to short bed coversion and I have a few questions about gas tank sending units.

I have a 74 1/2 ton with dual 20 gallon tanks, you need to switch to a 16 gallon tank which I already got. I'm only going to install one tank which will be on the passenger side, because I'm going to store air tanks under the drivers side after it's bagged.

Both my sending units from my 20 gallon tanks have 2 lines coming out I know one is for the fuel and one is for the vapor right? So how does a single tube one work? Does it not need the vapor line? I just don't know what all this stuff does exactly. I'm assuming I can use my old sending unit style in the new tank, but would I have to buy a different one since I'm only running a single tank?

[piecesparts]

Does your teruck have the return line from the fuel pump, also? The vapor lines are for the canister setup that many of the trucks had in the golden years of the early smog garbage. since you are in California, the smog cops will make it hard to make any changes other than what the truck originally had. My guess is if you are going to a single tank, then you do not have to worry about the sending units being different, because in those days, everything was most undoubtedly the same on both sides, you will have to eliminate the switching valve or block of the side that is removed.

[Captkaos]

Sending unit is the piece that drops into the tank. They will drop into the 16gal tanks.