1995 4runner 3.0l 3vze SR5

I am leaking so much oil it smokes down the highway from burning on my exhaust. I plan to drop trans & transfer case. Is there any advice anyone has, done this before that I should take into consideration? The seal itself looks like a piece of cake. Is there anything behind that seal, inbetween I should maintain while that stuff is off (without getting into make it too complicated) ?