Yes, their are aftermarket Gauges, you can use. You have to get a gauge with the correct "Ohms reading" (I cant recall the numbers right now) specs for mopar senders. I got mine from Jegs. 3 or 4 diffferent Gauge Cos have them. They will tell you the specs in the discription. Make sure its for Mopar tho.
Dave
Edit...... When I installed my aftermarket gauge, I tapped into the wire comming from the fuel tank (I thinks its lt blue color) at the botttom of the Drivers door pillar behind the kick panel. you have to cut the wire going to your dash gauge, as only one gauge will work, you can't have two gauges on one wire. So just tap onto that wire, and run that to your new gauge, along with the other wires. I did it on a 66 B-Cuda.