Here is tonight's progress. The bottom beams will be angle iron from a scrapped bed frame. I just have them as wood right now because wood is a lot easier to make adjustments to. They are bolted to the bumper the same as the angle iron will be. There are actually 7 holes in the bottom of the bumper so I can attach some triangular bracing down there. The angle in the top view is a bit steep where the boards are, so I will probably make the back end of the frame a little wider at the bottom.
Then my welder quit working.
The fan runs, the wire feeds, there is continuity through the gun and wire, but it just won't arc. Hope to have it fixed really soon.