I ran a roof rack that I made out of 1x1x.083 wall sq. tubing with 14g a plate for the wall gussets. I used 8 of the regular diamondrax gutter feet, and that mister of a roof rack saved my truck on a wheeling trip. It never really felt top heavy, but I was running it on my SUA FJ60 with heavy springs, I'm sure it would feel a little sway'y on my SOA 60. But as I was saying I was coming up a hill and there was a tree leaning over the trail, nothing I couldn't fit under, but the truck slipped and slide sideways into that tree and the rack hit the tree very hard, I only got a slight ding in the gutter by one foot, but the rack distributed the weight nicely.
Also, I had two piece of 1/8" aluminum sheet cut as the floor for my roof rack, and that was one of the best things I ever did, it completely shields the roof from the sun, so in the middle of the day in summer I could go out to the truck, with the windows cracked just a hair and put my hand on the roof, (I don't have a headliner) and it was cool to the touch.