eh, you and i both know that you're not going to make any serious changes to a 2400 lb machine with a 20 lb piece of metal, unless it's countered by that lower tie. Either way you're looking at it you're really only adding a tensioning spring and as long as the bar is flat stock and not square stock or bar stock you're never going to limit the up and down flex, the only thing you can hope to accomplish is limiting the amount the struts move towards and away from each other, and a steel piece of flat stock will be more succesful with holes drilled in it for these purposes.

Take a piece of fiberglass some time and try to tear it apart like a phone book, than take the same piece and try to snap it in half. I think this illustrates my points, but you're intelligent, so don't think im patrnoizing you.