Make sure the arewa between the bottom of the hood and the top of the thing that goes across under the hood is sealed also. If you run a trans cooler don't block the radiator with it.

At 45-50 MPH on the street my 499 KOS Demon would hold 180-190 but if I had to stop things got warm. I subsequently moved the trans cooler, replaced the improper fan with two thin ones (push and pull). It helped.