Bad alternator, battery, electrical? Dash surging.
 

Its a 98 Z28, basically stock, the battery is less than a year old, and i think i may have a failing alternator?
the Speedo/RPM guage surges randomly and it cant keep accurately still, but actual RPM and speed doesnt change
I notice its only when its warmed up and when i have a lot of accessories running (Cranked AC, stereo, etc)
could it be a problem in the guage cluster?
Will try to get a video up soon.

how many volts does the dash voltmeter read?

14? heres a small clip i got,
No gear changing/speed variation at all during this driving.

you cant trust the stock gauges.....get a voltmeter on it