Is there any way to PERMAMENTLY eliminate rear main oil leaks?

I used both fel pro and that fast fish still leaks not as much as yours but she leaky. Like a Harley marking its territory. Actually my Harley doesn’t leak lol
I buy whatever I can find on eBay for my /6... ROL, Detroit gasket, Victor, etc. I did use the "real" gaskets on the pan and valve cover of which I have 1 each up in the attic still. / Right after I bought those the "real gaskets" company came out with a more expensive line of the same gasket, I remember reading about it but don't remember what the difference was supposed to be. I already had what I do, so I didn't buy their more expensive version.
I do have at least a 1/2 dozen fel pro valve cover gaskets still in their package for a 80-down /6.

I have something to say about some of the fel pro gaskets though.
The ones that are the harder base material with the raised red or blue bands within have bitten me to where I've had to redo them more than once. Especially it seems on a small block or magnum timing cover or plenum plate on the magnums.
I've had to redo more of those than I care to remember, after having used what fel pro offers for these locations.

On one of my Durango's (the one with the 360) I replaced the engine about 60k ago. I got a good used engine for it with less miles. At that time I put it on a stand and completely regasketed it before I put it in. Along with the 1/4" solid aluminum plenum plate available from many places to solve the known problems of sucking oil thru that junction. I used the fel pro with the raised bead. Ever since I did that it's used about a quart every 1200 or so miles. And when I put the gas pedal to the mat sometimes id see a plume of blue smoke while I had it floored. I often buy more than I need "at the moment" from Rock Auto, stock up on parts I might not need today but know that I will definitely need for the vehicles I have as I tend to keep them til they're run into the ground.
Anyway one of the choices they had last time for the plenum plate gaskets were on a clearance and were Victor Reinz. Over the years I've used alot of Victor brand gaskets, I don't know where the "Reinz" part of their name showed up. But I seem to have better luck with their products than current day felt pro products.
I put the Victor Reinz plenum gasket on the Durango last time and finally solved the oil eating problem on that engine. It don't use any oil anymore between changes ... (Which I do around 4k miles)
Different material, it's a thicker, more conventional "gasket paper" material vs the super thin harder material with the raised up beads that felt pro offers for that application.
I have a head swap job and a complete rebuild job in the garage (2 different completely seperate jobs) that among others I will need head gaskets for both. I tripped across a deal on some fel pro Marine grade head gaskets for small block Mopar, that I bought enough for both plus 1 extra set for "just in case" while the gettin was good.
I first seen them on eBay for what seemed like a good deal "according to the gut feel" but there were only 3 available at least from that seller.
For the hell of it I punched that number in at rock auto and behold they had them for a few bucks a gasket less. So I threw 3 more in the cart while I was buying other (crap) from them anyway....well see how those work. I do have some more conventional fel pro head gaskets here that will fit the same engines/ I guess as a plan B.