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Why go through all that?
Find a used Knock sensor in the marketplace or craigs, If the motor is out it will be cake to change.
if its the secondary knock sensor (which I assume it is because he broke it putting in the motor) then its a piece of cake to install even when the motor is in.
@OP I suggest you go to a junkyard or go on CL and pick one up cheap, or look on HMP somebody has got to have one lol.