Help with thermostats

[rarias]

My Promax 225 engines while in low rpm / idle temp goes to 160F and then thermostat open and temp lowers, is this normal. Decided to change for new ones (143F). Now I order twice the Thermostats and say 147F ??? are this correct ??
488124

[XstreamVking]

Never seen 147 deg t-stats. 143 deg is all I have ever used in a 2.5. Got to be a mis label problem?
160 at idle is ok. Engine runs on t-stats for cooling at idle.

[rarias]

This is the rear of the Thermostat