63 Dodge Dart, now let me see;)

I would also check the rear seal as it looks like the lip is pointed to the rear. I do believe it should face into the engine. I cannot tell real well as I enlarge the picture my glasses cannot see as clearly as I would like.
You know what? I think you're right.
The red dot is the end of the seal and it's clearly pointing toward the rear.
rear main leak (1).jpg