Having a problem with leaking Pan on my Fordomatic. This is on a Transmission I just installed. Not a recent rebuild. I have installed a new Gasket which leaked. My Mechanic who has many Years working on 50's and 60's Cars installed another One today. Its leaking. The Vent is open. Pan Holes  have been tapped flat. It is leaking around Pan edge not somewhere else on Trans. Has anyone had a problem like this? Any suggestions?