Knock sensor ae101

[rollas22]

on my 20v silvertop 4age in my ae101 levin i just was conecting all the wiring up and found that i had a spare wire and couldnt find what it was for until i discovered i had forgoten to put in the knock sensor.
Problem:

there are two holes for it right next to each other... which one do i go for?
closer to g/box?
or closer to the cambelt end??

help ASAP