The Stovebolt Site Forums The Parking Lot Panels 'N Burbs FUEL SENDING UNIT

Hello Wise Ones,
Its been a few years since I have been to this site, but my big block panel truck is now a drivable usable machine.
Here`s what I have done in the last four years
swapped the origional 235/ 3sp/ 3.90 stock rear to
1978 suburban 454/ th400 (CPP tubular motor& trans mounts)
B&M quicksilver ratchet shifter
1972 12 bolt chevelle rear 2.70 gears
homemade 4"lift blocks welded to rear end spring over axle set up.
Sanderson headers 3" pipe with 3" glasspacks only 12" long (loud)
added power steering to the stock axle (CPP)
power disc front brakes with stock pedal (CPP)
tilt column (Ididit)
new wheels and tires (5 lug)
15x6 chevy ralley wheels up front
15x14 chrome chevy ralley wheels for the rear (hoosier pro street radials size 29x18.50)
electric windshield wiper conversion
installed new heater core
New gauge plate with autometer artic white gauges
speedo, oil, volts , water temp, fuel
(no limit)
It runs awesome and I have plenty of power to fry the tires and still cruise at 70mph all day.

The truck is a blast to drive and all the hard work, sweat blood and $tears was worth it now that its back on the road.
My only problem is that the gas gauge is reading a 1/4 tank when its full!
The gas gauge I ordered is a 0-90 ohm I was told that this will work with my stock sending unit.
I`m not sure if my sending unit is bad or if the signal (ohms) from my sending unit is the reason the gauge is reading is not correct.
I called my parts guy and was told that the sending units are not available for the panel truck gas tanks.
Does anyone here know what I can do to make the two work together or maybe tell me where to get another stock type sending unit?

Thanks, 59Ptruck (Bill)

Bill,

I can pretty well guarantee you that the 90 ohm/30 ohm combination will not read correctly, and to my knowledge, cannot be made to work.

If your gauge is 0-90, your sender must match it.

My guess would be you will have to find a sending unit that has the proper resistance, and modify it to fit your tank. Good luck.

Stuart

Thanks atomarc,
I just spoke with someone from the summit racing techline and I was told that the stock Chevy sending units are 0-30 ohms before 1965
and 0-90 after 1965 so if he is correct I should be able to swap
0-90 ohm autometer fuel gauge p/n atm-1315
to 0-30 ohm gauge autometer gauge p/n atm-1318
Can anyone here confirm that the stock sending unit is 0-30ohms?

Also my speedometer reads 39mph when I`m going 55mph
I have a th400 and the speedo drive gear has 43 teeth. They make a 39,40,41,42 toothed drive gears
does anyone know which gear I need for my truck
th400/ 2.70 rear gears 29" tall tires. my quess is the 41 tooth let me know what you think.
Thanks,Bill

Bill,

I can confirm that the stock sending unit is 0-30 ohms.

I'm very surprised you can get a brand new Autometer gauge for the 30 ohm sender...good for Autometer, and good for you!

Stuart

Thanks for the confirmation on the stock sending unit, anyone have any ideals about witch speedo gear I should get?
Thanks, Bill

59PTruck,

Yes, the stock sending unit is 0-30 ohms.

I also experienced an incorrect reading on my speedometer after a swap of manual to automatic transmission (TH350). I used a "Ratio Adaptor" to correct mine.

Brian