i have a 1971 olds cutlass supreme and my gas tank has a leak does any one kno if there are any other gas tanks that i can use

 

One way to figure it out is possibly go to a site that sells NEW tanks and start comparing part numbers. Not a guarantee but it might get you some leads. You will want to be year-specific as the earlier tanks didn't have all the ventilation ports/hose connections like the '71 and later tanks.