I am about to have a 3.73 gear installed on my 93 Z/28 and I don't know how to have my speedo calibrated for the change. I'm changing from a 3.23 to a 3.73 if that makes a difference.

 

Welcome.Might go to Search Forums up in the right hand corner of this page as there seems to be a boat load of info on this.hope this helps.(3.73 gear calibration)type in the box.

 

93 is the only year you can't recalibrate with a computer reprogram.

As far as I know, you have to change the gear that drives the VSS with the 4L60 automatic, and use an external calibration box like the Dakota Digital SGI-5 for the T56 manual.

https://www.camaroz28.com/forums/dri...speedo-299267/

 

I did exactly the same gear change years ago. The dealer told me that they could recalibrate the speedo. after the gear change they informed me they could not. I had to install an Abbott Electronic Ratio Adapter. It fixed the speedo, but the cruise control and ABS are not operating properly. I am looking for a set of NOS GM 3.23 ring & pinion to replace the 3.73 set. I have always had better luck with GM gears as opposed to the aftermarket. Good luck.