Freakin' water outlet won't seal!

This is going to sound really crazy and I believe it has been mentioned already but I'll explain what I found to be my leak and it may or may not be your issue. I too have a aftermarket stainless housing. I have had "seepage" around the T-stat housing of a tiny drop or two everytime the car was taken out. What I found was that my thermostat which is one that I have used for years in the factory housing and it never leaked a drop, would leak in the new housing. I played the same game with lots of RTV and other kinds of sealant, using way more than I usually did, but still had the weeping going on. So I took the factory outlet and placed the thermostat in it and it fit perfectly flush in the recess like it should have. Then I placed the same t-stat in the new housing and holding the housing upside down it appeared that the t-stat was sitting completely all the way down and flush on it's flange in the housing. Kinda by accident, I pressed on the stat on both sides by the bolt holes at the same time and I found a barely and I mean barely noticable movement back and forth,teeder todder. The inside of the housing is tapered where the nose of the stat sets. The top of my stat had a slight raised area around the center that was just tall enough to barely make contact with that inside cone area, causing the stat to be ever so slightly raised off the seat. So when I tightened it down to the intake, it would rock to one side or the other in the cone area of the housing causing an unstoppable leak, no matter how much rtv or gaskets you used. Went out and bought a new stat and the center area was smaller in diameter than the stat I was using so it fit in the pocket so to speak, perfectly. NO LEAKS. I have been chasing this for a while and with all the times I had it off I never picked up on the almost invisible bad fitment. If I had it off, I'd take pictures to show you, but it's on and not leaking so it stays put. Like I said, I looked this thing over many times and it looked like it fit in the housing all the way down flush, but it had just the tinyest bit of interfearance inside that housing that was almost undetectable, but that what my issue was. Long story, but a good find on my part. Good luck with your issue!