If you have done any work on teh 3.0. rebuilding a 22r is a breeze. I think rebuilding teh 22r is easier than changing the #5 plug on the 3.0, certainly less frustrating.

I would say since you have a basic diagnosis, and the engine is already partially torn down, I would go ahead and pull the head along with the oil pan. If the block and crankshaft are fine, you can rebuild it in the vehicle. It will be easier to remove the oil pan if you remove the front 3rd member first. Rebuilding it should run you under $400(get your stuff through enginebuilder.com), you might also consider getting the fuel injectors cleaned and rebuilt, usually runs about $30/injectror.