Knock sensors are piezoelectric crystals that create voltage from pressure (vibration), and are tuned/calibrated for the application. I suppose it's possible to swap out one for another while changing the location and have it work, but that would involve some serious engineering or extreme luck to pull off. I don't know what the resistance would look like on a KS, but I doubt it would tell you much about it.

If you're wanting to relocate it to a new sized hole, I would think the easiest thing to do would be to either a) weld two nuts together, one that fits the KS and one that fits a stud that fits into the hole, or b) weld a stud that fits the hole onto a nut that fits the KS.

That's about all I can help with. Good luck.