I know how you feel. I have the seven rack system in my fec with seven racks that I use to cook jerky, wings and sausage. I also have purchased four rib racks. I did do 40 racks once. You can read the whole report here.
http://forum.cookshack.com/eve...972932507#9972932507 to include pics and timelines. Keep in mind the rib racks will not work too well with Full spares. If you trim the spares into saint louis cut, they will work fine, and I'm certain Baby Backs would be a walk in the park. Remember and record your smoker hot spots and you need to rotate half way thru and spin all the racks. The Finished racks of ribs are not as nice and pretty and flat as they are on flat racks as some of them come out a little warped and twisted. But no one ever notices after they are cut. Doing 40 racks at a time was a big project. It took about seven hours. I've written a couple of posts, you can use the search button. here is another discussion with pic.
http://forum.cookshack.com/eve...232934707#5232934707