Hey kimber I installed a 440 in 66 charger heated up the same way, alot of people told me the same thing that 440's run hot! I took off the bumper filler and put in a 160 degree thermostat and that helped alot 15 degree easy, however i have jet coated headers that throw off heat like crazy the motor ran cool at crusing but i open the hood and man i could not touch the radiator support for the life of me. I thought about a scoop? but didnt want to ruin the stock look i bought header wrap on ebay but have not installed yet and i am positive that will even make a bigger difference. good luck.