Hey Clint, I've got a 59 chev with a 283 in it and also a 4 core rad. I've had a lot of running hot issues with mine. what I found worked the best for me was a fan shroud that kept the temp right down there now I can drive in parades. Also a larger or smaller (I forget which one it is) pulley on the water pump to get the fan and the water pump to spin faster helps.
