Rear seal or pan gasket?
 

I have an 82 f100 I recently purchased and is leaking oil bad. I removed the inspection plate and was gonna pull the trans and replace the rear seal but the fly wheel and the inside the bell housing was dry. Oil however is running down the front of the inspection plate appearing to come from the back of the pan gasket. Not sure which direction I need to go rear seal or pan gasket. Don’t wanna pull the trans if I don’t have to.
it’s a 4.9 I6. 300ci

Clean it off good with brake cleaner and a rag, and then run it in the driveway a little bit and then see if you can find out where the oil is coming from. Don't dismiss the back of the valve cover gasket and possibly any oil sending units or anything else that can be dripping and blowing back on the inspection plate area. If you can run it without taking it down the road that is best.

Yes, wash it and watch it.

Parts places sell blacklight dye that can be used to locate a leak if you don't want to go through the work of cleaning stuff up. As Dave said, it could be a few different things... look at the simple, small stuff first

i actually did that in the shop and there was definitely a stream of oil running down the center of the inspection plate on the outside or front of it. Would a rear main show there or inside the bell housing?

Its hard to say but if pan I would pull the motor to do that gasket than fight the pan & pickup tube to do that gasket.
Then do the rear main so you know both are done.
Did you see if the pan bolts were lose?
Dave ----

you’re right ! I believe I’m gonna pull it. Needs head gasket and lifters too. Easier to do all that when you’re standing next to it!

And on a stand.
When rebuilding my truck the motor was covered in dirt & oil so I replaced the valve and side cover gaskets and pan gasket, no signs of the front or rear seals leaking.
Got it on the road and have an oil leak but from what I can tell its not the seals but looks to be the timing gear cover :-arrgh
I need to clean it up and do a good look over to see just where its coming from and fix it I hate it is leaving its mark at work.
I park in the same spot at work and it kills me to see the oil marks and got cardboard down in the my garage to save the floor.
Dave ----

FWIW, a few weeks back I tightened the oil pan and valve cover bolts. Give them a little twist/snug with a 1/4 ratchet and socket see if any are loose. I found most of mine were.

:-missingt I just did that today on mine and like you mine were lose.
Heck 1 of the pan bolts was missing so that could not help matters much.
I still think the gear cover is leaking on mine but I hope I slowed down the oil spots on the floor some.
Dave ----