Help with leaky tank on ’67 Dart

Ok, the bad boy starts leaking last summer. I got a new gasket and lock ring, after siphoning off the gas to the Saturn, I knock the ring on the tank loose,( I also notice some featherhead has pushed/knocked the stop on the tank to where that doesn;t stop ANYTHING) Okay so I bend back the tank stop,replace the gasket and lock ring and fill it up 2/3 in case in DID leak again. well, hell, it does.

Plans are to siphon off the remaining gas in the tank, remove the fuel line and fill the tank with deep blue dyed water and see if it's the sending unit or the tank.
Unless someone else has an opinion or idea, I'm sure open to it.
Author: admin