Has it been stripped or wrecked? The grizzs' have had a digital dash since at least 2003. and if it has you might try ebay...pick up a used one for a grizz.

 

Open the tank.......look inside........shake the machine side to side and watch the swishing......... lol....... that's pretty much how I check the gas in mine......

Of course my Rancher has a gauge and you can buy aftermarket drop in gauges....