[MrWillys]

I run a fully welded 28x19 Howe Aluminum. I thought the Griffins use epoxy on the tanks. I bought mine from performance bodies. Here's the link.
http://www.performancebodies.com/store/product.asp?dept_id=530&pf_id=342A
Mine shown here is an early model. If your CJ is 72 or later, you've got lots-O-room.