That is interesting on your support rods not being slotted on top, After I posted I went back to that parts manual and blew up the picture of the support rods and they are definitely slotted. Hopefully someone with a 9 apart or a good memory can shed light on this. I am not sure if you are doing a concourse resto but if not and you have welding skills I would just take measurements cut and lengthen the rods if it becomes to much of an issue, should only be a half hour job and if done right would look clean. Good luck and let us know what you find.