You know when they say always start with the basics?
Wasn't fuel related at all; distributor rotor had a hole burned through the center, and the cap was corroded to heck.
Replaced both, runs fine with no misfires.....a GM technical service bulletin (included with rotor) warned of a ventilation issue inside the cap, leading to premature wear and failure......they recommend that you make sure the vents in the distributor housing are clean, and if you have a screen over the vents, remove them!
Also, if you have an AC line near the distributor, they recommend you cover it with a 9 inch long piece of foam to keep condensation from getting into the distributor.
Lastly, found my next project....at some point, the front cap bolt had been overtightened, and the mounting boss on the distributor (that holds the cap in place) was cracked in half and broken off; I'm hoping some JB MetalWeld will work to fix this!
MT-2500, thanks for your help!