Tank Assembly problems of the 1999 GMC Sierra 1500

The first time I bought the vehicle it overflowed fuel when I filled the fuel tank to it's capacity. I assumed a vent line was loose, but knew it would be a big job to drop the fuel tank and check, so I just limited the amount of fuel I would fill the tank with. On Jan 5, 2007, the fuel pump quit working and after dropping the tank no vent line was found to be loose. Upon further investigation, I determined the fuel pump mounting flange on the tank was about half connected, thus where the fuel would leak from when the tank was filled to capacity. It appeared the mounting flange is fused on and there was not an adequate bon made. It was on about 1/32" wide for 180 degrees and only about 1/16" wide the other 180 degrees. I have since repaired the tank using a product called jb weld and also installing (4) #10 machines screws with washers and locking nuts holding the flange to the tank.