Gauge to measure KR?
 

So with all of the talk about mods and KR in these parts, I haven't found anything about where to get and how to install a simple gauge to measure how much KR is occurring. I'd like to, but not sure where to start. I'm also looking to invest in a scantool with a GM add-on which I'm sure would do it, but I've seen something simpler installed before to serve just the KR piece. After all who wants a full (probably laptop based) scantool in the car all the time!

You're looking for one of these: ZZ Performance

a lot of people use the GN gauge