ok ur ls block should not have a spot for a knock sensor, you have to tap one....
second if you did tap one,...... u should have tapped it where the plug will reach...
dont fear however because the knock sensor is only one wire and should be cake to extend.....
Last it depends on which ECU u are running some do not have knock detection....
if urs does u will get a CEL for the knock sensor CODE 23... if it does not there is no need to hook up the knock sensor....