How high should the speed go on the speedometer of a 1993 Camaro Z28?

I have a '93 Z28 and its speedometer only registers 115 mph. I've been looking around, and every other Camaro I've found has a speedometer that ends at 150 mph. This could just be a medial problem if the speedometer was just set wrong at the factory, but it could be SERIOUS if thats as fast as it will go. Any answers will be appreciated, Thanks.