I am getting a rear end with 3.70 gears, Right now I have stock 2.73 gears, what must I do to recalibrate my speedo?
Since my car is a 92 I have a VSS I believe, so what do I do?

 

until someone who knows for sure replies, you may be able to find out some info on your own using http://google.com search engine., there are pages on the net about this here and there,

terms like speedometer calibration, VSS, etc,.

good luck

 

You have to change your speedo gears, both the driven gear (in the VSS) and the drive gear (in the transmission). What is your tire size, it is needed to find the right part number.
As far as changing them, it's easy. The vss has one bolt holding it into the tailshaft of the tranny. To get to the drive gear, you have to pull off the tailshaft. The parts are about $10 from a GM dealer. Get a new clip to hold the drive gear to the output shaft.
You will probably need a 15 tooth drive gear, and 42 tooth driven gear, but like I said tire size will change mainly determain the size of your driven gear.

 

Can anyone confirm what Truckman said?

I'll go to the dealer to see what they say but they aren't very bright. When I went to them to ask about buying a crate 350 and they looked up the 350 for a 92 Z28 and when they found that particular engine was no longer made they siad no other engine would work.

So I have little faith in what they say.