As Roger said, put the shroud on. Air flow is very important. Do you have a plate over the grille at the hood latch to keep air from going over the radiator? That makes a big difference. Also look at air exit if you elect to put the hood back on. The air should have a large area by the back of the front wheels to exit. If you have headers and they seem to contribute a lot of heat, wrap them. Your temps are not bad, use the 195 or 190 thermostat not the 160. If it warms while sitting, as long as it does not overflow and will restart, as Roger said, it will cool right down.