Oil temp is important as noted above to minimize water/acid build-up in the
oil. But the 180F T-stat indicates when the stat begins to open, not the temp your engine will run at. The engine operating temp "DEPENDS". That will depend on comp ratio, timing, AFR, total power, water flow, airflow and rad efficiency to name the big ones. If you are really running 165-170F upper hose temp in summer ambients, you have a great rad and great water flow, be happy.
You didnt mention the ambient temp or at what road speed your at when you see this temp. Are you using elec water pump or belt driven? In general, you want an upper hose (engine out) temp to be about 190-195F in ambients up to 90F. If ambients go up to 110F in your area you will see upper hose temps near 210F-215F as "normal", it of course depends on water flow and rad eff. I would expect the 501 to be putting out quite a few hps and 165-170 F is great if true, unless you have a monster rad, tell us details about your rad if you can.