Perfect, thanks :thumbup1gif:I cut the slot for the shackle mounts by drilling a hole at each end of the slot and connecting them with my plasma cutter. It can pierce 3/8th, but it's cleaner and easier on my consumables to drill a starting hole like that.
The second question, I'm not quite clear on what you're asking, since it kind of has two top hooks. The answer is the same for both I suppose, I cut a tight fitting piece of 3" flat bar for both sides. Pushed it into the tube to a spot I liked and set the welder on "kill" and zapped them in. They're only welded on the one side I could reach of the flat bar, but 6 inches of total weld (3" each end) and no problems.