I have a 54 Customline Coupe with a 85 5.0 with a AOD in it. I recently did a filter and fluid change. I ran into a little issue when I dropped the rear of the pan to drain the fluid, the rear lip of the pan hit the rear trans cross member. It wouldn't drop enough to let the pan drain very much. I had to pick up the rear of the pan and drop the front of the pan. Just a heads up if you have the same setup. My torque converter has a drain plug so I was also able to drain it. I put a drain plug in the trans pan while it was off also. Sorry I don't know what happened to the order of my pictures? Pay no attention to the bear, he's always hanging around.
Unless you are planning on doing a lot of off road driving, or something else that would twist the frame a lot, I would trim that flange off the crossmember. On my Dodge truck, the trans pan won't come out of the hole its in without removing the transmission crossmember from the truck, and that is all factory equipment. I don't have a hoist, its a pain doing that on your back laying under it! I'm sure happy I installed the pan drain the last time it was off.