Quick note....

While driving to my parents house to take the kids swimming I was thinking about Docs suggestion to mount directly to my stanchions..... I like it. The front most mounts will have the mounting bolts only about 2-2.5" away from the edge of the rack, and with my stanchion design there really wont be much cantilever action at all. If anything the problem would be with the rear most mounts if the edge of the rack interferes with the bolt head... but the bolts might end up being just off the edge of the rack.

When we get home tonight I'm going to make a quick model of what I think would need to be welded on the rack. Basically just 6 L-brackets that are 2" wide and have some gussets for stability.