340 Rear Main Seal Replacement
Keep in mind that with 86,000 miles, there is a fairly good chance (in my opinion) that the crankshaft may have a bit of a groove in it where it has spun inside the rear main seal billions of times. I have seen it many times. And often, a stock seal won't help much. I have seen over sized rear main seals for chevys, but I don't know about Mopars. I really do hope you come out OK.