need help! identifie correct gastank

[monster77k10]

I have a 1977 k10 400/turbo350 and the previous owner installed a small 7gallon fuel cell. So the gas gauge is not hooked up. I can't figure out what type of tank or tanks were in the truck originally so I can mach the correct sending unit to the original gauge. I do know there are two lines running from the fuel cell but no signs of wire leading from the gauge.

[zieg85]

Welcome from NW Indiana.  Our trucks, if a shortbed had 16 gallon tanks.  If it is a long bed it could have either, usually if it was a single tank it had a 20 and if it had dual tanks, I have seen both a 16 or 20.  The tanks fit either side, the sending unit is side specific.  Your 1977 would have had the primary tank on the passenger side of the truck.

[monster77k10]

Thank you for the quick response. Am I able to just put a single tank and sending unit in and still hook up the original gauge? I'm not a fan of duel tanks.and yes it is a short bed step side.

[zieg85]

Make sure your bed has provisions still.  You will need the filler tube/hoses to hook to the bed/tank.  You will need the tank cradles and straps if yours have been removed.  The hardest thing to find would be the correct filler tube if yours is missing...

Over the years beds/bed sides could have been changed out.  If yours is still original to the truck the filler tube hole should be on the passenger side.  If you have a filler door on the drivers side the bed has been changed

[monster77k10]

Would you happen to know the original gas gauge ohm readings? I might just go with a larger fuel cell and sending unit to mount in the bed. But need to know what ohm readings the gauge takes. I'm guessing 0-90 or 240-33?

[zieg85]

0-90 ohms

[monster77k10]

So I've been reading up on fuel cell foam. Everyone has a different opinion. I'm looking at a 16gallon summit fuel cell and I'm wondering if I really need to worry about slosh. Honestly if I don't have to I rather not have foam. One less thing that could go wrong. Opinions?

[Captkaos]

I wouldn't put the foam in a truck you plan to drive.  If it is a race car fine, but that stuff degrades. 
If you have a short bed your only option is the 16 gallon tank, Long bed could be either.

[Low87]

So I've been reading up on fuel cell foam. Everyone has a different opinion. I'm looking at a 16gallon summit fuel cell and I'm wondering if I really need to worry about slosh. Honestly if I don't have to I rather not have foam. One less thing that could go wrong. Opinions?

Are you thinking of putting a Summit fuel cell in the bed?  If so, please let me know and listen to my experience first.

[Captkaos]

Are you thinking of putting a Summit fuel cell in the bed?  If so, please let me know and listen to my experience first.

Tell us how you really feel Low87.

[Low87]

Well, it's a really awesome idea if you like the rain water additive in your fuel system.

[monster77k10]

I did put in a RCI fuel cell in the bed but I did think of the rain snow and dirt problem. I made a hinged box that fits over it to keep any rain snow mud etc from the top of the cell.

[Low87]

That rubber o-ring will fail soon.  I even had some water get into the fuel system when I moved the fuel cell under the bed.  Never did figure that one out.