Where can I find these seals?

I have never seen a rubber seal at the bottom of the steering tube on any A body and I have had a bunch of them ....I have seen wafer donut type seals up inside the tube usually made of that bigger bubble styro stuff....but I have never seen a seal on the end of the tube.....and it would have to be on a 4 spd or floor shift auto, because the column shift manual and automatics have some pretty large slots up high on the tube and a seal down at the opening of the tube would just trap water