Awesome, thanks Lane and Gordon - nice hearing from you guys!
The only time I ever had anything similar to this was in Carlisle at the Speedster meet. The car was running really rough and popping. SOC came to the rescue with a little in-field carb cleanout. I didn't have the overheating and dying out issue ever before though.
So, since I did just run Seafoam through it, sounds like the most likely is some crud loaded up in the jets? If they are clogged, I'm assuming that would also run him lean and cause overheating, true? I have a great VW mechanic up here locally, but it's really time I get into doing the carbs myself (I have, after all, had this car for 10+ years!
Thanks again for the responses and support. Looking forward to Carlisle next year!