So, you took all the manual shift parts out of your column? Not surprising that there is a big air gap in there. Well, the auto column that year has a different column tube that holds a seal at the bottom. With the cut-out on yours, that seal won't do you any good. You'll either need the other column tube, or rig some sort of boot to go over your opening. A tube from a '63-6 A-body without manual 3 speed column linkage should work, except for the '65 models with automatic on the column. A floor shift manual trans tube, or, the '63-4 automatic tube would be the best one to use.