ahh, perfect. I went to the local do it center and they had 2x8 flathead screws, so I got a half dozen of them and some nuts for them.. spun the nuts down to the head too my hand dandy dikes and cut the screw in half, then backed the nut off (to fix the boogered
threads) and out it in the topcap.. Ahhhhh.. perfect air flow. no adapter needed any more.
and as a bonus, I got to clean out all the sludge from one of my topcaps, so it's not funky any more.