Megasquirt knock sensors settings

The 5.7 hemi has a bore size of 94.49mm, so the knock frequency should be around 6-6.1kHz. As far as sensitivity, that's something you'll have to find out on your own. If the sensitivity is too high, you'll have false positives. Too low and you'll have knock and no retard. If you find you're picking up too much non-knock noise in the frequency range of an actual knock you can instead use second or third order harmonics (2nd=12-12.2kHz, 3rd=18-18.3kHz) to kinda isolate the knock, but you'll need to tune the sensitivity again for that.