Here's the only problem I can see, and I want to state out right that I am trained as an airframe mechanic and all we do is lay alum and rivets. The metal can be as thick as you want, as fancy a shape as you want, the problem is unless it's welded along it's edge then the ONLY strength it will get it from the placement and amount of rivets used.
In this supports case there are only 7 rivets, that's 7 points on which the peice will be torsioned or stressed. Only 7 rivets means if a hard hit is taken and one of those rivets loads up (which it will since less rivets=more stress on each rivet individually) it will rips the tunnel and give way.
What's the fix? More rivets, placed strategically. I have a set or krom's supports and he did ballance the loads properly, if I remember correctly there was 16 or so rivets in EACH side. Check out where his are riveted in the pics supplied in his thread and I would apply the same rivets in the same spots to get the most strength out of your support. No bashing intended, just someone who knows this stuff helping another guy out :beerchug:
EDIT: I just counted mine and it's actually 19 rivets per side. Remember more rivets is more tie downs which equals more strength. Just like laying 2" of weld is more holding metal than 1" of weld. hth
