I hear you there Stacey.. I am going to run the cars out of the shop and start building an Ark if it doesn't stop raining here pretty soon. Good luck with it! JW
It was the fuel cap! Previous owner had a locking, non-vented cap on the fuel tank. Apparently the fuel pump wasn't able to pull enough fuel against the sealed fuel system - that was enough to cause lean surging at part throttle. It runs 100% better with a vented cap. It still has some crap gas in it that is probably four years old but it runs well enough for me to believe it will run better once I the old fuel is gone.