Replacing rear main seal - in situ (engine in car)

Hi.
Visiting from A bodies only.
Car = Factory 69 383 Formula S 'Cuda.
32k miles, engine never been out AFAIK, but many leaks around the oil pan.
I'm trying to keep the car as original as possible, so not going to take engine out and clean things up "while I'm in there".
I'm definitely going to try and remove pan and R&R pan gasket.
May change rear main seal while in there.
Any tips on trying to install new main seal in an oily mess?
I shouldn't have to loosen main caps and "hope" crank drops a bit right?
Just remove rear main seal holder????
I know about offsetting the parting lines.

It's been > 40 years since I've been into a B engine, don't laugh but remind me which way the seal faces. Lip to harmonic damper or to flexplate?????

Thank you.

Engine shown below, rebuilt carb and funky dizzy cap, but shooting for how it may have looked in 1971
Craig

Nice car! 383 Cuda! Yes, you'll probably need to loosen the main caps to drop the crank
down to give you a little wiggle room. If the crank drops down without loosening the caps
you've got bigger problems! The seal lip goes towards the front of the engine. It's gonna
be tight! Good Luck.

While you are in there, replace the crap Mopar rear seal retainer with a quality billet piece. I had chronic rear main seal leak on my freshly rebuilt 426 Street Wedge in my '64 Polara 500 convertible. I bought an aftermarket rear main seal kit from Mancini's and that fixed it. I had to loosen main caps and let crankshaft drop a bit to get top part of seal out.

Just did my 383 last week. I was able to just use a narrow punch and hammer to tap one side up and able to grab the other end as came around. The old seal was a black type and came out rather easily. It was kind of brittle when I got out so be careful you don't break it while trying to pull it out. If you have a rope seal still in there, it might be more difficult. Read the "Official rear seal blog" in the engine forum a few times, it has great info especially for engine in car. Good luck.

In my experience the rope seals seem tougher to remove. Typically one of the old kits came with a thing like a cork screw that you were to screw into the end of the rope and then pull to remove the seal. That never worked as planned for me anyway.

The labyrinth style seal I've had best luck with pushing out using a small diameter piece of nylon rod. I took a larger diameter section and machined down one end to the size required. (I can dig it out and post a photo if you'd like). That approach was flexible enough to follow the crank radius some amount, but stiff enough to allow it to force the seal to move. Usually an inch or so is more than enough to allow you to grab the seal from the other end and then pull, but as has been pointed out, continue to follow the radius of the crank so you don't break a portion of the seal off that is still behind the crank.

I did it once to a 383 by putting a rope type back in. I got lucky, I didn't loosen the mains, just used a small screw driver to start and then gently tugged and rotated engine. Then the rope went in rolling again. And it went from leaking a drop every 30sec when running to maybe a little on the floor occasionally.
I wouldn't bet I could ever have that luck again!

Thanks for the feedback.
Got oil and trans pans off yesterday.
May re-think RMS replacement since TQ converter rear face is completely dry.
I'll take a closer look and see if any potential leaks were just blocked by the "splash shield" at lower edge of trans case.

I was wondering if I'd find a windage tray installed and I did.

Cheers

Craig