I did a search and found some posts about this but it doesn't sound like what I'm seeing.
When I'm driving and floor the gas the tachometer and speedometer needles both move rather slow and kind of bounce up and down as they move up. The car is running very fast and pulling hard while this is happening.
I've never seen gauges act like this before. So is there something wrong with them that I can fix?

 

When my tach bounces like that, there usually is a burned plug wire or some other ignition-related miss.

The only time my speedo bounced was when the vss was on its way out.

 

It feels really really fast so it's running too good to have a miss I think.
If my VSS is going out and causing this would that be hurting my performance any? How much do they cost? and where's a good place to get one?
thanks

 

No, the VSS going bad will not affect the performance of your vehicle. I have no idea how much one would cost though. All i know is dont buy the replacement at autozone!!

 

Just take a look at the plug wires and make sure that they haven't touched any exhaust pipes or anything, even though the car runs strong, you could have a burned plug wire.

Get the vss from the gm dealer. I think it's like 40-50 bucks, and installs pretty easily.