The block is a '91 L98 from a 'Vette so it did at one point have a knock sensor in it but I have had the engine carbed since I've owned it. Now I'm converting it to efi but I can't get the knock sensor in more than like two threads because it's hitting the oil pan lip. From what I see there's only one spot per side of the block to put it in. I'm going to use a close nipple and female/female adapter to set it out from the block about an inch, will this affect its readings?

 

I wonder if you're using the correct hole? Been awhile since I looked, but seem the recall it's no where near that close to the pan.

I know that doesn't help with your specific question.

 

It was the only hole I could find tapped for NPT. I got a close nipple and female coupler and that worked fine.