Instead of welding the bolt head could you make a sleeve and weld that in the hole instead? Just thinkin' out loud.....

 

Not going to weld the bolt head. I'll just overlay a 3/16 to 1/4" plate with a perfect 9/16 hole in it and plug weld that to the face of the bracket. Pretty standard jeep repair for the cheesy track bar brackets they put on them. The dodge bracket is a lot thicker but the truck also weighs 3 tons so the effect is about the same when the bolt is loose.