is the back of icm a ground?
 

i have a 95 z28 6 speed new plugs/wires new opti. my question is. the back on the icm is metal (aluminum or w.e) is that a ground to the head? and could be what is keeping my car from fireing?

thanks

No, the black wire, pin C is the ground.
shbox.com has the diagrams.

Al

The back of the ICM is a heat sink. It should be touching aluminum to transfer as much heat away from the thing as possible so it doesn't cook itself.