well you know I am having the same problem you first had. I put a new magnum 360/380HP crate motor in my car back in april. Put new alum radiator and new 180 perf thermostat. I have no shroud. New viscious fan and clutch and the car was running hotter then I think it should with everything being new. Tried bigger radiator and a 160 t/stat still ran hot. Tried no t/stat still ran hot. Thought about going to a 19" flex fan but really did not want to spend the 50.00 for a fan and it not work. So I will try changing my lower hose to a flex style with a spring to rule out the hose is sucking shut and causing the water to stop flowing. All you did was go to the flex fan and now you cant get it warmed up. I also have a trans cooler infront of my radiator but it not blocking the whole radiator only a part of it.