Thermostat temperature recommendations
What temp your engine runs at will be determined by the engine.....& cooling system.
Never run without a stat; it is the restriction in the system & it creates pressure [ by deliberately causing a restriction ]. This suprressses localised boiling in hot spots [ eg, near the exh ports ].
If you have an extremely efficient cooling system, & a 160 stat, the engine will run just slightly higher than 160 [ the opening temp].
If the engine runs hot, the temp rating of the stat will have little impact on the actual temp the engine runs at.