Percolation? Heat soak? Don't drive during summer??

Radiator is brand new cold case radiator, fan and clutch are brand new, transmission cooler is brand new, WP is brand new, spacing is correct between the fan and the rad. Timing is set correctly (was done by a FABO member, he hangs out in the racers forum though.) I cleaned the water passages as much as I could when we did the cam swap and pulled the heads off. I think I have a 180 or 190 thermostat, the 160 might be the way to go.

The 160 won’t help. It sets the minimum temp before the thermostat opens.

Max temperature is controlled by coolant flow, air flow, air temperature and probably 1 or 2 things I’m forgetting.

I’m all for a 160 thermostat. Just not for the reason you want it.