no hac in rig,would like to put one in.
Just goes to show what a great filter the radiator is.I installed a low-miles rusty 2F engine and after a while, the rust flakes plugged the radiator (began to overheat on the freeway - that was my clue).
A new radiator and more flushing and all was well. My engine had sat in a shed with an open cooling system for 11 years and the inside of the block simply rusted as you would expect it to. But, all that rusty crap has to go somewhere, and that somewhere was the radiator.