My 73 K20 has a 383 with 10:1 comp. Aluminum heads and around 425-450HP. I have a re-cored radiator out of a truck with A/C. (I dont have A/C) I am using a hi-flow water pump, hi-flow 160 degree T-stat and a 17" Flex Fan with fan shroud. I am still running too hot. What are my options to cool this thing? Do I have to spend $600 on an aluminum radiator??