I am currently putting in a 5.0L in my CJ7 and was planning on putting a YJ tank in to use for an in tank pump, but yesterday I figured out the YJ's are a few inches wider in the back and the tank won't fit. So, I am thinking about just putting it in the back between the fenderwells. Is it a bad idea to put a plastic tank in the back (a couple of feet away from me)? Should I build a metal box to go around it for safety reasons? Is it illegal to have a tank in back with no cover?

I would like to buy a fuel cell, but money is hindering me right now.

My brother is an excellent SS tig welder, should I just have him weld me up a box with baffles in the bottom, a couple holes on the side at the top for fuel, top hole for pump, and another hole for vent? If this is a better option, what thickness SS? Is there anything different about weldeing a tank together than normal SS that I should tell him?

The tank in my TJ is lifted into the tub and surrounded in metal to keep any fumes out and to it doesn't take a good hit.