This is the 12V Fuel Gauge and Sending Unit setup I used in my CJ3.

I bought my 2" fuel gauge at the local parts house, but they didn't have the CP7583 sending unit to go with it.
I did a web search for SunPro Gauges, and came up with Actron Mfg. ( http://www.actron.com )
Below are excerpts from their online catalog. (I shure hope they don't mind free advertising....)
The hyper links should take you to their online store, to the specific page the gauge and sending unit are on. (I hope)

Sunpro Fuel Level - CP7950
Sunpro Fuel Level - CP7950
  • E - - - - F range.
  • 60 scale
  • Requires CP7583 fuel level sender

The fuel gauge bezel matches my speedometer bezel shape, fuel gauge was chrome instead of paint. 
Guess I'll have to look for replacements for the other gauges in the same style.

Sunpro Fuel Level Sender - CP7583
Sunpro Fuel Level Sender - CP7583 For use with fuel level gauges and 5-26" deep tank. Includes gasket and mounting hardware.

The sending unit was a direct bolt-in, well actually screw in replacement for my CJ3's steel fuel tank.

Just a few notes here:

Be sure and check Actron's Online Store Terms and Conditions. I ordered my fuel sending unit, and got it 3 days later via UPS, just as requested. No problems.

The gauge and the sending unit mounted right up, no drilling or engineering required. Just a bit of adjustment on the sending unit for the correct tank size. So far no problems. I would set it for a 5" tank instead of 5 1/2" like I did when I put it in. If it was at 5" instead of 5 1/2", then it'd have a bit of reserve after E, and be showing full at the bottom of the filler neck. Next time I have an empty tank, and the seat off, I may just readjust it.

To try and make sure I had as good a ground as possible, I ran a 2 wire lead to the sending unit in the tank. Both were right off the gauge connections on the back. Ground and Sense.

I don't fill my tank to the very top, it'd be coming out around the gas cap. But the bottom of the filler tube is about 3/4 tank, and that's what it read when I did my normal fillup. Tank drained it was right on E, and I poured back in 4 gals that I'd drained, it was just under 1/2 tank. Looks close enough to me.

I have noticed after a fill up, the gauge is a bit slow to pickup the new level. It could be a good thing, not such an erratic reading is it doesn't sample the level as often.