Help me choose, I'm torn between a 160* or a 180* high flow stat. Engine is 1969 440 375 horse mostly stock except for a small Comp cam and Edelbrock performer intake, 391 gears. Car is a 69 Dart GTS so because of the small engine bay and big 440 motor not much air can circulate around the motor under the hood. What thermostat would you recommend? Thanks..