cherokee laredo

I'm thinking about buying a 1985 Cherokee Laredo 4x4. 154,000miles, with the 2.8 and an auto transmission. According to the current owner the valve lifters make a noise of some sort. What could this be. Would I have to replace the valve lifters? Other than that it appears to drive well, and the transmission seems good. Also how much would the issue with the vavle lifters cost to sort out? What should I look for on this Cherokee, and are these generally reliable? I'd mostly use this for hauling stuff to a nightclub, but I might enjoy doing some simple offroading later on.