Gas Tank Leak repair what are my options??

oil was drained but the oil pan was still on car when i jb'd it. i had my torsion bars really low and hit a piece of dried concrete stuck to the road. the dealer wanted 700 bucks to fix it in 1988. the jb weld was 3 dollars, im sure if the gas tank is finished draining it would be worth a shot to try the jb. if it works great! if it doesnt 150.00 for a new tank. no biggie