I purchased one of Speedhut's programable fuel gauges for use in my 71' Dart with aftermarket replacement tank and sending unit. I programmed the gauge to sending unit while it was out of the tank and everything looked like it was working correctly. My issue is with the gauge fuel level drop, with a full tank of gas the gauge will stay on full for a very long time, but once it starts to drop below the full mark the level will drop all the way down to below a 1/4 tank in about 30 miles of driving. I'm thinking this is a problem with the sending unit and it's short float arm. I don't know how far I can go a 1/4 tank as I really don't be stranded on the road side. Guess I might have toss a gas can in the trunk and run the car out of gas to find out for sure.