I'm having the exact same problem? :evil: I have a 10 1/2:1 540 in a 3100 Monte Carlo, Griffin radiator 3000 cfm electric fan..had it pulling air from the back side of the radiator, now in the process of moving it to blow thru the radiator. I also had a 160 thermostat, then put a 190 in and no luck. Also, tried taking out the antifreeze and put in straight distilled and water wetter..which I believe kinda helped? I did put a March underdrive pulleys on, which still didn't help...HELP!!!??? Think taking out the thermostat and running just a restrictor will help me too? Thanks in advance for the good info already!