These days, there are many options when it comes to temperature sending units for the water temp gauge. Of course, you always want to use the sender from or recommended by your gauge manufacturer. Classic Instruments supplies the sender with their panels and gauges, and even has this sender for the 12mm metric thread for use in LS heads. This was a lifesaver for me! Make sure not to lose the small washers that are on the post of the sender and to put them back together in the order specified in the detailed instructions.