Fuel sending units

[Doug Long]

My son and I are working his newly purchased 1976 K20 long bed, special deluxe, camper special. Our goal is to restore it this year and get it to hot august nights in Reno, NV. Is there a way to determine what type of fuel sending units are in the tanks prior to dropping the tanks? He found out the hard way that they don't work when he ran out of gas.

If not we will plan on dropping them this weekend. So far we have dressed up the engine (350) with some chrome, new plug wires, new plugs, adjusted the carb, and put a new 4 core aluminum radiator in it. He ordered new tires and we sent the old wheels off to get powder coated this week. Shocks, breaks, fuel tank sending units, and diagnose an oil leak are on tap for this weekend.

 

[idahovette]

@Doug Long you gotta have pics or @Rusty Nail will be all over you!!!

 

[oldretiredafguy]

I'd be curious as to what brand of fuel sending units the forum members have chosen?

 

[Powerhouse Ranch]

When i had restored my Jimmy fuel tank ('88 with fuel pump in tank due to fuel injection) i ordered the one out of LMC. Its been working great honestly. Just ordered another for the parts truck, cheapest i could find at my local O'Reillys. Yet to see how it goes. I think it may be Spectrum brand, Autozone was doing a more expensive Delphi. So i'd suggest LMC, determine as to how many outlets you have and then order the one for your truck, assuming you obviously have a saddle tank(s)

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[HOTFOOT]

I got 2 OER authorized for my 80 gmc with 3 outlets from Classic industries , remember different sending units left side right side

 

[oldretiredafguy]

Thanks guys. I always worry about ordering something with as many sensitive parts as a fuel sending unit, and then trusting UPS/FED EX to not play tackle football with the package. I worked on a freight dock before joining the military, and saw what my fellow dock workers did to some lightweight boxes. I realize that all packages go through some handling prior to arriving at a retail store (NAPA, Advance Auto, etc) so all items are probably a craps shoot. I hate to install something, then figure it's not working properly, then disassemble the whole shooting match and start all over again. Lots of experience over past decades doing just that.

 

[SirRobyn0]

Other than the before mentioned number of lines being different, they are all the same. Right and left sides, 16 and 20 gallon tanks are all the same. Later model FI were different though.

At the shop we have been Spectra brand sending units which are manufactured by.... You guess it. WIA, so not an American made part unfortunately but we have had to warranty zero sending units built by them so that's a good.

 

[oldretiredafguy]

Thanks. I'll try Spectra as the chosen brand. I need six, two for the '83 crew cab, 2 for the '86 C20, one for the '88 V-Jimmy, and one for the '91 V-1500 Suburban. Maybe one of the retail shops will give me a quantity discount for six!

 

[Powerhouse Ranch]

Thanks. I'll try Spectra as the chosen brand. I need six, two for the '83 crew cab, 2 for the '86 C20, one for the '88 V-Jimmy, and one for the '91 V-1500 Suburban. Maybe one of the retail shops will give me a quantity discount for six!

Holy sending units Mike!

 

[Doug Long]

Thanks, I included a couple of picks from this past weekend. The body has very little rust. We are going to drop the tanks this weekend and determine what to buy. The rims should be back from powder coating Friday and the tires should be in Thursday. I will post a couple more picks once the tires and rims are back on. The rims are getting powder coated cardinal black.

 

[AuroraGirl]

I got 2 OER authorized for my 80 gmc with 3 outlets from Classic industries , remember different sending units left side right side

Spectra Premium FG05F Sending Unit for General Motors​

I purchased that for my 80 gmc on the driver side. cant actually attest to the sender working or not i havent fixed the gas gauge wiring yet but it presumably is working. no issues. it came with a o ring and lock ring and I didnt realize it would so i bought them separate. Seem decent quality.
no evap system because over 8600 gvw so had a vent valve on the vent line.

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@oldretiredafguy Even tho I have no working gas gauge atm the sender has been on my new tank since 2019 and tho I dont use it like a normal truck so it doesnt see gallon after gallon, i measure my usage by hours not miles etc, its been working fine and the sender is been rather exposed too where its at so not rusty at all.

 

[SquareRoot]

Other than the before mentioned number of lines being different, they are all the same. Right and left sides, 16 and 20 gallon tanks are all the same. Later model FI were different though.

At the shop we have been Spectra brand sending units which are manufactured by.... You guess it. WIA, so not an American made part unfortunately but we have had to warranty zero sending units built by them so that's a good.

The ones on my 85 aren't the same. The ports point opposite directions, either toward the frame or away from it. They are not interchangeable. The tanks however are identical side to side. The vent hoses, once again are side specific. I have one delphi and one doorman. They look identical. The main tank (D/S) is fairly easy to find, the aux tank (P/S) was a PITA.

 

[SirRobyn0]

The ones on my 85 aren't the same. The ports point opposite directions, either toward the frame or away from it. They are not interchangeable. The tanks however are identical side to side. The vent hoses, once again are side specific. I have one delphi and one doorman. They look identical. The main tank (D/S) is fairly easy to find, the aux tank (P/S) was a PITA.

That's actually right and someone else mentioned that they are different side to side. And truly they are. However most aftermarket manufactures these days only make one. As you said most commonly they make the left side only, and putting it in a right tank really isn't an issue the fuel line outlets face the wrong way, but that can be dealt with by using slightly longer hoses to run the line behind the sending unit and then to the metal frame lines. It might sound a little less than ideal, but in practice it works just fine. If I think to I'll lift the bed on my truck and snap a pic of the right side sending unit as mine is set up that way and has dump kit on it so it's easy to get a look at.

 

[SirRobyn0]

@SquareRoot and anyone else interested. This is what a left side sending unit in a right side tank looks like. As you can see it is possible to that and have the rubber lines neat, organized and safe. Going on three years like this so far and hasn't been a problem.

 

[Bextreme04]

Thanks, I included a couple of picks from this past weekend. The body has very little rust. We are going to drop the tanks this weekend and determine what to buy. The rims should be back from powder coating Friday and the tires should be in Thursday. I will post a couple more picks once the tires and rims are back on. The rims are getting powder coated cardinal black.

If neither unit is working, I would suggest looking at the gauge and wiring before you just replace both sending units. The dual tank switching wiring for the gauge is a bit convoluted and has quite a bit of areas where you could be having a poor connection that could cause it to not read right.