First post, not a car person though I try to impersonate one every other Saturday at the Community College working on my '74 FJ40. A couple years ago, I took the gas tank out, used POR15 putty on all the soft spots and then painted it with POR15. It's held well until a couple days ago when it started leaking again. I'm thinking of just getting one of the 12.5 gallon poly tanks. I don't need to worry about DEQ here because I'm one year under the date where it's required. I put a Weber carb on and just closed off the three ports on top and the one for return fuel. I got a vented gas cap and it's been running fine, though I only drive it in and out of the garage and in and out of the the work space at class (tow it there). My question is do I need to worry about continuing to block all those ports with a poly tank?