Hey guys. I'm helping a freind get his SC back together and we can't remember what is supposed to be filling this hole? I think it's for a sensor, but I'm not sure. Thanks!
There is an adapter that threads into the block, and then the knock sensor screws into the adapter. The parts are different for 89 - 93 compared to 94 - 95.
Ed is correct, The knock sensor adapter screws into the block first and then the sensor screws into the adapter. Theres also a sheetmetal protective shield for the sensor as well. Post if you need pictures of the parts and I'll put them up for you.