I had to modify the way I did mine because I have a welded in roll pan so in order to get the tank out I would have to lift the box, but in order to bolt the box down the tank has to be out of the way. Here is what I came up with to solve all of that.
First off just made a square frame out of 1/8" X 1 1/2" flat bar.
Then drilled holes in the flat bar to match the holes in the tank.
The curve of the frame causes a gap at the front of the tank.
closer look at gap
to fill the gap I used a piece of 3/8" X 1 1/2" flat bar, and across the back I used a piece of square tubing with flat bar on the ends to make it bolt in, didn't take a great pic of them but you can see them both in this pic. Cross member is hanging on the left side.
Here is a pic of just the frame bolted in, I welded nuts on the top of the frame for the 4 bolts on the frame rail, and then just tapped the flat bar and tubing across the front and back.
And here is a final shot of the tank installed.
Hope this is helpful to someone
Very nice job!!
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