Sensor locations on 360 magnum

Holley Sniper is what I'm running. I would have spent a bunch more $$ for a Holley EFI with spark/knock control.

I just checked, the Terminator X has the provision for 2 knock sensors. Also, the other big feature is that it looks like I will be able to wire in the the OE crank trigger. The system is another $500 over the Sniper, but as you said, I am willing to pay for those features. The only question I have, is how do you add a knock sensor, to an engine that did not have one to begin with?