my car had the guage face changed, as well as the backlight. the guage now reads up to 150 mph, so i thought that may have been why it said i was doing 80 when i was probably only doing 60 - 65... but i checked my odometer out on a mile marker and im 2/10 of a mile off.... rest my mind, what was the top speed on the original speedo in 95 for a Z28? and if its not what i have, why do they make them with 150mph? and how do i fix it?

 

If you checked your odometer reading and determined that you are 2/10 off (over, i.e. 1.2 miles) after only one mile then that's 20% error which is very significant. That would cause you to read at laest 72 when you are only going 60. The Z28's do have 150 MPH speedo's, it's most likely that your gear change caused the error. You can get the PCM reprogrammed with the correct gear information.

 

3.73 gears any mail order tune or even a hypertech can take care of that

 

the odometer and the speedometer are two diff. things. so basically your odometer is still accurate, but the reading on the speedometer is off due to you changing the face, obviously. what did your speedo read before? 115? in order for it to be accurate, you'd need to get the speedo calibrated (not the same as pcm calibration) at a speedo shop. youd be better off getting a 150 speedo from a car thats being parted out. now as the other guy mentioned, if you replaced the gears in your rear end and didnt have the pcm calibrated for that, you need to do that also.
chris