knock sensor location

I just received a package with a couple of sensors among which a knock sensor (type used in 86 corvettes). Is there anyone that knows where in the block it should be mounted ( i have a early 70's 400 ci block)

Most all of the TPI type systems have it in the driver's side low down in the water jacket, near the mains in the drain plug hole....I think it's 3/8 npt tap....

now there are two differant types of knock sensors, and they are NOT interchangeable, they looks the same as I recall....but the ones for a '85 vette will not work with a 1227730 speed density computer for instance....so you gotta match the correct one to the computer,

:bounce::smash:

Thanks Gene !

Knock sensors used with the fender mounted ESC unit contain an internal 100 kOhm resistor. The up-integrated ESC units (contained in the ECM) require a knock sensor with a 4 kOhm internal sensor. The plastic connector is different color on these two sensors (100 kOhm sensor has a white connector, the 4 kOhm sensor has a black connector). An ohmmeter will easily read the internal difference, too.