Over the river . . . and still q-less

[Michael Murphy <mmurphy@nais.com>]

Dear list,
Thanksgiving Day, gave us (me, assembled family (no more than 700lbs),
89 100 FWD) the opportunity to go roaring down the LI Expressway (Rt
495) Eastbound (towards summer playground in Southampton, NY) @
3800-4200+RPM (speedo gave up 2 days ago) so figure 75+MPH.

Around  3500RPM (I have a 3sp slushbox), on non-incline road, an
increasing "hum" developed what sounds like a harmonic, with variable,
but regualr osolating frequencies, "hum"; that goes away at ~3400RPM.
I've got an out-of-round RF tire that gives very minor feedback through
the steering wheel (love the way these cars "talk to you") and will be
"fixed"
tomorrow with new front tires that are high-speed balanced this time.

This "noise" is new and  makes me think of  worn motor/trans
mount(s).  Any BTDT or thoughts ?
TIA,
MJ Murphy