[19Fordy]

To my knowledge there is no type of seal in that location. It's a pretty snug fit when all is screwed down. You could probably use some "dum dum" putty seal if needed. Here's a bunch of photos that I posted as I have them. I bought all my seals from DRAKE many years ago when he was in Canoga Park, CA and his catalogue didn't show a seal for top of transmission floor pan. "Kube" would know for sure. Heater color is not stock.