What are you looking for as far as temps go? And at exactly what point do they start to rise uncontrollably?

The only other thing I can suggest is you do what I did and remove your thermostat. This will keep coolant flow constant throughout the system. Some people do believe otherwise with that theory like the coolant needs to be slowed down and stuff along those lines. Its worth a shot if nothing else and takes all of 10 minutes to try.