I am selling a never used sumped fuel tank for 1970 Challenger. I welded the tank up using a new gas tank and competition engineering sump. It has been leak tested with compressed air and soapy water and I didn't see detect any leaks. I didn't treat the inside with a gas tank sealer because I was planning to run E85 with it and I worried about it eating the sealer up, but I recommend treating it with something like POR15's gas tank sealer to prevent the welds inside from rusting.
I had every intention of using this tank, but because my fuel pump cannot pull fuel I would have to mount it below the sump level which is just more trouble than it's worth so I went with a fuel cell.