Everything is brand new, still overheating.

[jccatwb]

Am going to agree with 'gunslinger; you can move the water too fast. For adequate cooling you need an adequate volume and area to transfer heat. My heating problem was solved with a re=cored radiator with 50% more volume and 50% more area for heat exchange. You have to move air through it, too. I found a 6 blade stainless steel flexfan worked far better than the original - and it is much, much lighter putting less stress on the water pump bearing.