Spent sometime on the fit of the step 'plate' to the side skin, using the 'adjuster' mallet to good measure. Without great effort, the plate was quickly bent to conform to the skin surface for what appears to be the majority of surface area.
Drilled one #40 pilot rivet hole to secure the position and establish a starting point. Needs trimming of the Aft lower corner to eliminate the corner which cannot be bent enough to conform.
Even with the plate flat against the skin, the tube length is insufficient to properly reach fully into the UMHW block. Any attempt to secure the rotational force by drilling through the tube/block assembly would fail. The gap is 7/16ths" and cannot be eliminated with further adjustments.
Mike Cycon added a 1/4" nylon spacer between the UMHW and the rib (and appropriate adjustments to the UMHW block/rib bolt length. Sounds like a good start, but still too thin. My concern is the torsional load on longer bolts by adding a spacer. If done, I think it needs three or four 'through rib' bolts ... will contact Vans support for an opinion.
Need to clean-up the hole shape and debur (side skin and F-623 rib).
