kodalee

I have a 93 z 28. How do I re cal my speedo

93M6Formula

Your '93 doesn't have a 4L60E, it is the non electronic 4L60/700R4.

Two ways to do it on a '93.
1. Replace the speedo gear in the trans (Auto only), which are getting hard to find and aren't always accurate for custom setups.
2. Get a calibration box and wire it in between you speedometer wire and the VSS. This is the best option because you can calibrate it to be exact for whatever your setup is. This is what I did in my car.

This is what I used and it's great.
http://www.summitracing.com/parts/dak-sgi-5/overview/

96capricemgr

iTrader: (1)

Might also consider changing to a 94-95 pcm which is easier to reprogram and I think would deal with the speedo issue, give you heated O2s and MAF if you want it.