The 223 has solid lifters and they are shaped like a top hat. To replace them, the camshaft has to be removed and the lifters come out the bottom although you may be able to see the top of them by removing the metal panel on the passenger side of the engine block.
I suggest checking the valve lash adjustment with a .019 feeler guage and box end wrench for adjusting while the engine is running (at normal operating temperature).
If the feeler guage feels too loose, tighten the nut or screw on top until it sounds like Pffft-pfft-pfft and then back off until it just begins to sound like clack-clack-clack. Dont forget to tighten the locknut (on older style rockers) and be careful not to let the screw turn while tightening the locknut.
Successfully completing this procedure may help your situation. If you engine compartment is kitchen table clean like mine is, you will want to tear off a piece of aluminim foil and scrunch it over the intake/exhaust manifolds prior to running the engine with the rocker arm cover off. The remainder of oil splatter can easily be cleaned up with Dawn dishwashing liquid and hot water.
