As with many, a clear drone noise starts at 3,300 rpm and continues upward.
The noise only occurs under load - ie when I run at 3,300 rpm standing
still, drone is not heard. As for tone, most of my auto aware friends
hearing the sound think it is either exhaust or air intake related.

I have done a lot of troubleshooting/work to date releated to Air Cleaner,
Exhaust, and Alternator, as follows:

My final question is at the end.

AIR CLEANER WORK TO DATE:
1) wrapped air cleaner in 1/8 inch sound dampining material. Maybe slight
change, but no big change.

EXHAUST WORK TO DATE:
1) **Per many comments on this list, I have hung my muffler from the frame
and inserted a second flex coupling between the cat and the muffler.  Cat
rubber mount removed, and cat hanger mout now bolted solidly to engine
block.  Maybe slight change, but no big change.

ALERNATOR WORK TO DATE (AND QUESTION!)

1) removed belt from compressor to alternator.  Noise stopped!
2) removed/reinstalled compressor and alternator making sure all bolts
belts tight.  Noise still present.
3) Installed second brace to alternator (1/4" x 1' steel bar running at 45
degrees from altenator axis from the alternator lug to engine block) to try
to stop any vibrations. Noise still present - maybe slightly different tone.
4) Did test with car in place, like before, no noise
5) I wiggle the alternator shaft and feel only the tiniest bit of movement.

I have not bought a new alternator for $150 because, well it cost 150 and
my questions below:

QUESTIONs

I am confussed!

1) If my alternator is in fact out of balence, why does it not "drone" when
reved in park?

2) Is it possible, that my alternator is in actually balence, but that the
Ticco mount/alternator/belt assembly is resonating?

HELP!