http://www.z1motorsports.com/product_in ... ts_id=1727
http://www.twinturbo.net/nissan/300zx/f ... ation.html
try looking at these two. top one is explanation on det sensor, the second one is the relocation.
if you want to spend the total least, but leave your car unprotected without a knock sensor, you can get this
http://www.z1motorsports.com/product_in ... ts_id=5580
but if you do the relocation, on the first link, there is a link for the triple covered harness, I would recommend that and just get a sensor from ebay, mine was 30 bucks and if it doesnt work, i can send it back. and the second link up there explains completely how to do the relocation, 3 different spots.