Thanks for the advice Bob - I did notice the low IAC counts on this motor, even at low RPMs. Questions:
1. Am I right to think that I should first verify no other vacuum leaks are present before tweaking the throttle body set screw?
2. I have not cleaned the IAC on this throttle body in awhile. A cruddy IAC should result in higher IAC counts, not lower, correct?
3. Is it worth trying to clean the idle air spider plenum (without removing the intake manifold, preferably, or even possible)?