When I restomodded both my '64 Falcon and '66 Mustang, I swapped to '69 Mustang 20 gallon tanks. Bought the (supposedly) correct F/Q senders. One of my gauges is Ford, the other is AutoMeter. Neither one reads correctly - both about a quarter tank low. I gave up fooling with them and just figure my fill-ups by the odometer. One other point - my Falcon is a 5.0 swap like yours and my fuel tank is not baffled around the pick-up. When I get below a quarter tank of gas I sometimes cavitate the fuel pick-up when going around sharp corners, causing the engine to stumble, then recover. You may not have this issue, but I thought I'd mention it in case you do. Have fun with it!

 

I have a new fuel tank/ sender/ and the fuel gauge still will not work. How did you know the gauge was bad.How do you check the wires, there isn't voltage thru them is there? I haven't been able to get an answer. Is it a rheostat?

 

Well, I performed SuperSabre's test on my oil pressure gauge. It's been stuck on 10 ever since I installed it but when I disconnected the wire from the sender and grounded the sender wire with the key on, it only jumped to 30. That's all it would do. After I shut it off, it dropped off a little bit but not back to zero.....or 10 even! I'm guessing it's a gauge problem.....

 

Well, I'm glad the test procedure worked even if the results were not to your liking. I would agree that the gauge needs help. Though I've never taken one apart, maybe you could take it apart and gently blow it out or look for other things that might be impeding the smooth operation of the needle. At this point it can't hurt! For Scott Lathropp - the checkout procedure for the fuel gauge is the same as 37 Ford Guy's oil pressure gauge. Have one person turn on the key and watch for the fuel gauge needle to travel to full while the other person has removed the sender wire at the fuel tank and grounded it out. If the needle travels to full, the gauge and wiring are OK and you have a sender issue.