Thanks for the question.
Usually the valves don't need to be adjusted on this engine since it uses hydro. lifters. But if it is needed, you would tighten the nut till there was no lash, then turn 1 full turn. As well there is a specific order of doing it as well.
However, 2 years of sitting, I would definely start with putting in fresh fuel. Adding octain boost and a treatment would not be enough to off-set an entire tank of bad fuel. Start by getting new gas and clean the plugs with some brake/carb cleaner and we'll go from there.
Since you adjusted, did you run the engine prior to parking it for 2 years?
Bad gas can still "burn" in the form of pre-detenation or actually being ignited correctly, but still may not run right. Wet plugs is definetly a sign that the fuel is not igniting properly. Now, the valves could play a role in this, but it the lash was set properly prior to parking, then I don't feel that they would come loose just sitting there. There is one other thing you can try. Pull the fuel pump fuse or relay and try starting it using carb/intake cleaner. Of course it would only run as long as you are spraying enough in the intake to keep it running, but it if does run off that, then the fuel will be the issue.
Yeah, start with that and see what happens.
You do not need to pay until we get this working, unless you want to. Otherwise, I'll just leave this post open until you return and let me know what happened then we will go from there.
I'm on the east coast too (Atlanta) , so just let me know tomorrow, I should be here.