I'll have to post some pics of mine. You can't buy a 63 Rambler wagon tank, or anything close enough to modify! I basically took the old tank out, took some measurements, then devised how I wanted it to fit.
I made the ends first in the profile I wanted. I allowed a 1/2" flange to be bent all the way around. I planned on using a universal sending unit, so I made the front top of the tank slant about six inches back from the front at about a 30 degree angle so the sending unit would go in without hitting the floor. Rather than make only a small area slant, I took the easy way out and slanted it all the way across. The tank is deeper at the front than the back -- about 8" in front, 4" in the rear. I used a piece of exhaust tubing welded near the bottom of the tank for a filler pipe, and have a vent coming off the front slant nearest the top. This is similar to the original tank. I ran the tubing about 8" inside the tank instead of just welding around the hole. That allowed me to weld the bottom edge of the tube to the floor of the tank well inside, strengthening the filler neck. I made a third "end" to use as a center baffle and pump mount. I cut the corners off and made two "pie cuts" near the center about 2" deep so some gas would flow from side to side.
After the ends were made, I cute a piece of sheel metal to "wrap around" all but the top. The very top, which is flat against the floor, was left open. I just used a #2 non-hardeneing sealer and 1/4" hex head self drilling screws around the top. It isn't be submerged, just get some splash. I welded a length of 5/16" brake line in for the pickup and a return line (I have EFI). The fuel pump is mounted at an angle on the baffle with a pair of u-bolts (3" exhaust clamp bolts). I put a 1.5" tall baffle across the front about 2" back from the front to keep to much fuel from sloshing away from the pickup when taking off with a low tank. I can run it down to about 2 gallons before it quits (don't ask how I know... ran out of gas this morning -- need to fix gauge wiring!!). I just stuck the stock Jeep in tank pump in (engine is a modified 4.0L six) with the pump filter sock in the lowest part of the tank.
To make sure it didn't leak, I soldered the overlaped seams on the edges. I have a cheap MIG welder, and even though I used gas, I still had some pin holes. The soldered seams don't leak! I smeared epoxy over the welds where the filler neck, vent, and fuel lines went in as well. I filleted the welds with epoxy where I thought a little extra strength would come in handy. Before I put the top on, I brushed Hirsch (
www.hirschauto.com) gas tank sealer over the plain steel surfaces, and over the seams. Figured this would just be insurance, and keep it from rusting inside. Note that Hirsh doesn't recommend brushing, but it works fine.
I've been driving with this thing in for about five months now. I do have a leak due to the sealer -- but that's because I made a mistake when measuring! My "wrap around" was 1/2" short in the back. I tried epoxying in a filler piece then lapping the top over is with sealer. The sealer washed out in a corner -- it will only work where there is a good bit of overlap and practically no gap. It only leaks when I fill it nearly up and go around a corner or take off -- when gas sloshes into that ##%$ corner!! I already have the fix -- a new back piece that I will epoxy and screw in. I don't like welding on a tank that has had gas in it, though with the whole top off ther can hardly be any fumes.
I'll post some pics, in this thread if I can figure out how, in my album if not. Will post a follow-up soon!!