Help !! #6 Rod knocking after very low oil

[Rogue_war]

So lets see if can put this across, I ran my 1988 Cherokee Limited 4.0L out of Oil. (I know I know), it died on me in traffic. had it towed home, I also had some battery charging issues. Got it home towed home and the charging issues taken care of. also at the same time I replaced all the upper vacuum lines.Now I have a very loud knocking, its really more of a loud Dull thud. I had my brother In-law/mechanic come over and listen to it. He said with out pulling it apart it sounds like the #6 rod is bent and suggested draining what Oil I put in it, and adding new oil and some type of really thick oil additive (the name escapes me).
and that sooner or later, it would throw it out. I am at a loss can I fix this with out a total rebuild or a new long Block.

[Junkpile]

You starved the bearings when you let it run out of oil, ad now you probably have excessive bearing clearances and the "rod knock" that comes with it. At best, you need a new set of rod and main bearings when a rod knock starts to creep up... but you probably skipped right over the best case scenario by running it dry.

Figure out exactly what it is and then fix it ASAP. Right now you might just need some new bearings... maybe some turning on the crank... possibly a full rebuild including cleaning up the bearing saddles. But, If you try to drive it like it is, it might end with a broken crankshaft or a rod poking through the side of the block.

Then again, could be something else... I doubt it, but it could be. Get your brother-in-law back over there to help you take it down and see what's wrong.