1979 Dodge D150 Gas Tank and Sending Unit Replacement

I swap the Lil Red Express truck's fuel tank with one that's not so beat up. I also replace the fuel sending unit that was reading fuel level incorrectly. 00:00 Pulling The Tank 01:32 Testing The Sending Units 06:42 Install Sending Unit 15:00 Testing Unit At Empty 15:31 Install Gas Tank 27:24 Testing Fuel Levels 31:38 A Leak?