I took the vent off. I also removed the middle section of the air inlet vent and sprayed it with Pam cooking spray so the gasket material wouldn't stick to it. I then sprayed the side of the ash bowl with Pam around the area where the vent mounts so gasket material wouldn't stick to that either.
I reassembled the air inlet (slid the middle section back in place) and put the blue, ATV gasket making material around the perimeter of the back side of the air inlet. I also filled on each end of the rectangular opening to fill the gap between the middle, slider section and the rectangular opening.
After waiting 10 or 15 min for the gasket material to skim over, I put the air inlet back on the ash bowl and used the screws to pull the air inlet down but I didn't tighten the screws. I let this sit for a day and a half for the gasket to dry/cure. This morning I shigged the screws up and mounted the ash bowl back on the CG Kooker for the seasoning. It seems to have worked ok but I haven't yet cooked on it.
It doesn't take much air to maintain 400F - 500F. This surprised me. CG should make the rectanguler air opening only 3/8" tall so you would need to slide the air opening much further to get 450F. From what I read in this thread, barely open to closed is about 250F, 3/4" open is 450F-500F (my experience). So will 2" open run 700F? Not sure how I would measure temps that high since the gauge that came with the unit is up to 200F off at the higher temps (probably depending on how well the heat is directed toward it). I don't think I have a temp gauge that goes to 700F. My wife is at the grocery store today picking up steaks.........so I'll figure out something! <smile>