I wouldn't use a temp sensor in that position, instead plug in a sensor at the
hottest point of the system (pre-radiator) and then after (at or pre-block).
Like Stainless eluded, you probably won't have time to watch both, but it
may be helpful in data acquisition. The "post" level is what's really important
but it's nice to see how well the cooling system is working.
We use the same thinking with boost (pre-intercooler & post-intercooler)...
We pulled boost reference before the IC, after the IC, and post TB to gauge
where it really is during dyno pulls, then use the intake port for racing. That
has usually been the most equalized under load (16 psi on the track vs. 19 psi
on the dyno). Without data, you're just another guy with an opinion