Temp probe RPM Air Gap

Hello Everyone. I have a 68 340 with the Air Gap and am adding a Dakota Digital fan controller, which requires the temp sender to be electric. I have a mechanical temp gauge, so I need to purchase an electric temp probe.

I have labeled the picture below with what I have currently. Can I use either of the two purple arrows for the new temp probe? If not where else can I put a second probe?

Thanks!