First Truck

[rbharris1984]

Hello all,
My first swb and first post. I hope to find lots of info and want to say thank you in advance. Traded a 1998 jeep cherokee for a 1982 swb that is in need of some work. Couple questions, first is if this truck came with a 10 bolt 8.5" posi rear from the factory and I'm having a knock around cylinder 6 that i can feel in the valve cover. It is only when idling and doesnt affect driving but it is very noticeable. I had a misfire so i replaced plugs and wires which solved the problem of misfire only to have a knock the following day. I drain the oil which has no metal in it and removed valve cover, had my wife tap the ignition and everything seems to be moving freely. I'm just wondering if something could have been stuck or needs adjusting. I have searched and searched the internet and forum. I dont even know if it is stock because it has aftermarket intake manifold, carburetor, and has a nice lope when idling. Sorry if it's too in depth or repeated.