if its making noise, it could very well be a bad head gasket.
if it is the lifter, it could be as simple as oil residue/ sludge preventing correct lash pressure.
may also be a loose rocker arm.
things to look for/ common problems:
remove air cleaner and look inside throttle body with a flashlight, you are looking for heavy oil residue - leaking plenum gasket - lots of work to get to, there is a $300 kit that replaces the plenum plate with a stronger piece to prevent warping and future leaks
heater core
steering box - wears quickly, esp with 4wd and larger tires - several upgraded models made stronger and better (redhead), some may require you purchase a new shaft as well
ball joints - time consuming to replace
vacuum system control a bunch of stuff and has issues...
-air condition switches to defrost under heavy acceleration
-cruise control doesn't work on hills
-4wd is vacuum controlled and may not disengage
cracked dash - $300+ for replacement, lots of time or $40 cover (if you have to replace the heater core, might as well count on replacing the dash as well)
cup holders the flip down are terrible design and will break so that they can not hold anything of weight.
4wd - track bar (or pan hard bar) attachment point at frame will loosen over time/ worn bushing/ bolt hole damage/ etc. and cause death wobble
