I've read a lot of stuff about clicky/tappy lifters and rockers in wranglers. I pulled them out of my 2.5L to take a look at them because i recently had a big clicking noise appear. The lifters are a just starting to get concave, so ... new lifters and camshaft soon. (I could actually look down with a flash light into where the lifters were and see the cam wear. Not terrible but there.)
But!, I cleaned the oil muck off them with a brass brush as well as cleaned the oil paths in the rockers and guides and ... clicking is highly reduced / gone. It will come back as the lifters and cam wears I figure. But hey ... removing them was easy (at least in the 2.5L) ... gives you a good idea about your camshaft health ... and may help.
p.s. here's a nice argument i found for why you need to replace both the lifters and the cam. Go down the page to "Replacing worn tappets and cams." http://www.v8engines.com/engine-4.htm#v8gen
Basically boils down to: If your lifters are worn , your cam is worn. If you put new lifters on a worn cam, the cams going to wear them back down in a hurry.
p.s.s. Make sure if your going to pull your lifters out with a lifter removal tool, the tool has a real good grip on the lifter when you pull. If you drop them while you're pulling them up out of the engine you get to chase them around down there and try to stand them back up so you can get a hold of them again. REALLY fun. ... Not that I made that mistake ... but ... i knew this guy who had a friend who did ... just saying.