Gas gauge in 72 Tahiti

[hkunz]

My old gauge in the Tahiti hasn't worked for a few years, and the anticipation of when, not if, we would run out of gas is just not as much fun as it used to be. So, i bought a new gas gauge, 0-90 ohm, thinking that with an Olds engine, there'd be a GM sender. I also got a new fuel cell for my second tank, and it came with a 0-90 sender, so everything should be good, right?
I put it all together today, and the gas gauge went nuts. I may have ruined it, i don't know, but anyway - Does anyone know what the sender would be in a 1972 Tahiti jet boat? 0-90 GM style didn't work. The tank is 12, maybe 15 gallons. Steel tank, with crimped ends. Thanks!

[SleekcraftHouston]

When all else fails, try pulling the sending unit and measuring the resistance at both extremes. Any gauge you buy will have the resistance values printed on the side of the box and probably on the gauge itself.
My guess is that your original was a Stewart Warner, VDO, Faria, or Teleflex type gauge (240 - 33 ohm). Your local marine retailer can help you measure your sending unit if you don't have a multimeter. Just make sure you cover the hole left in the top of the tank when you pull the sending unit out.