piston rings
You will be dismantling pretty much every piece of the engine in the process of doing this. If you don't already have a Factory Service Manual you need it for all the specs. Not much diff in the years, but there are some. The FSM has details for complete engine rebuild. Also go to slantsix.org. In particular - look under 'articles' for manifold install and main seal/oil pan install.
Many manuals are available at
http://www.mymopar.com/index.php?pid=109