First, RRR, what were you doing awake and on FABO at 4am???
Second, DUH!!! Of course its lean... You ever get so fixated on something you ignore the obvious?
I was so hung up on the fact that I backed the idle screw all the way off, that I didn't pay attention to the clues the car was giving me...
1) Its getting hot (lean condition)
2) Part-throttle cruise surge (lean condition)
3) Diesels occasionally (lean or timing)
4) The carb is making that "lean whistle"
Thanks all for setting me straight! It better not be a bad manifold... this one is cast iron, so hopefully I'm good there. I'll let you all know what I find!