On my Runner, I made plates floor plates that matched the interior floor plates on the cage. I bolted them to the interior floor plates which sandwiches the floor pan between the plates. Then I made some fish plates that were welded to the frame. Finished it off with welding the correct diameter and shape of DOM tube to tie them all together. I didn't seal the bolts that go through the pan. No need to run the cage tubing through the floor pan in my opinion. Hope this helps.