i installed a autometer 5" tach and shift lite on my 92 350 with stock ing. system. I'm pretty sure its wired correctly the wire wire commin out of the dist. goin to the v-8 wire on the tach. the problem is the stock tach gague and the autometer tach don't read the same they are always about 100 rpm off from each other?? is this normal or is something worng?

 

I'd say fairly normal, the Autometer will be the most accurate one of the two.