When the dealer did the first valve, they replaced it and put everything back together before allowing me to see what they found. They didn't even pull the other side to check what was going on over there. Told me it had to be bad gas. I am not sure if they checked the injector.
Funny, but I've been doing a lot of local digging talking to gearheads & tuners I know, and several told me to check out a place local & see what they think. Little did I know, it's a place that tuned a small block in an old Bronco I had 20 years ago (showing my age, now)... They did a great job then, and do their own machine work. I'll talk to them about what I've seen posted here, and see what they say. If I feel confident they have someone there that is compentant enough to make me feel warm & fuzzy, I'm going to ask them for a full eval of the problem. I am pretty sure, regardless of the reason it's happening, I am going to need one or more valves, so will get the initial tuning/firing/injector/whatever problem fixed, plus machine the heads & replace the valves with a matched set.
Thanks for the post, SleeperMaxima - I'll update the post as I see what the frig is up...