So my son bought a 66 and we are restoring it. All new wiring, gauges, CVR and fuel sending unit. Here is the issue. I have verified the resistance behind the fuel gauge to verify that the correct amount of resistance is matching the full tank of gas. Also verified the CVR is pulsing and the correct voltage. I also bought another "new gauge" from CJ's and both gauges do the same dang thing. When the key turns on, the gauge goes all the way to full and then falls to under 1/2 full on the gauge. I have beating my head about this and after hours of checking and double checking, I am reaching out for my sons sake so he can drive this thing without running out of gas. Any thoughts.