I have a 94 S-10 4x4 w/ 4.3 vortec CPI - 143,000 mi. The engine starts fine when cold.
After a short warm up, the engine would start to Skip and Misfire, Real bad under load and when hot.
EGR Valve was Clean. Found a bad Ignition Coil. $15.99 @ Auto Zone
Tim from Connecticut

Tough one.
New wires, distributer cap, router, and new plugs should take care of the miss. And since your so close, do a full tune up at the same time, and your S-10 will thank you for it in return