Knock sensor having an issue finding the hole to screw the bolt back on the knock sensor that is supposed to be located on the back of the engine block somewhere?

Hi, I'm having an issue finding the hole to screw the bolt back on the knock sensor that is supposed to be located on the back of the engine block somewhere? I accidentally took it off when and didn't need to when I was changing my lower and upper intake manifold gaskets. The back of the engine is very dirty, and I've tried wiping it off the best i can but still no luck finding the hole to put knock sensor back on truck.

I'm using a mirror and super bright lights but still can't find it. I see plenty of holes on the back of the lower intake manifold, but none are the ones I need. I've searched and searched online/ YouTube and am getting different answers for different locations on back of block. If you have anything that would help me, I would greatly appreciate it so I can get my truck back on the road ASAP. Thanks