I run the Derale 7-blade fixed pitched fan from BC Broncos, metal fan shroud, smaller waterpump pulley, etc. I did the whole thing at once, so it's really hard to tell what single modification worked the best for me. Yes, it does cool well in the winter, however, I have a 351W & they always seem to run hot no matter what. I just recently added an auxilary cooler, so it also helps keep the temps down...