Prior to the disassembly of my project 65 Clone GTO the gas gauge worked fine. Now with new tank and reinstalled dash and about half a tank full the gauge does'nt register, just sets on E. The float works fine tested it prior to reinstalling in the new tank. I get the same Ohm reading to the gauge but no reading. I did a simple clean up of the faces and new clear gauge cluster cover during the process. Am I missing something??????? Tank is grounded to a good ground in the origanal hole in the rear trunk flor pan everything checks out. I have a 64 gauge cluster they don't interchange and gas gauge mounts differently in the back plate of the cluster or I would just swap them.  

WOW i have a 70 gto and when i did mine. same thing. under my rear seat. i found a wire. it was split so i repaired it and that solved it .good luck