Flex-a-lite cooling fan, Do the work well

[stringpickin]

Hello and good day. I have installed a flex-a-lite dual electric fan on my 70 chevy pickup on my brand new 383 engine with Edelbrock EFI.. My engine has about 60 miles on it. It has gotten towards a hundred degrees out for the first time this year and today, as I was doing the final break in runs, my engine peaked at 221 degrees.. SCARED me to death.. I had to turn my truck around and go back down the highway hill, and it did kool immediately down. Turned back around go up, and it did the same thing again, I pushed it a bit further up the hill and repeated the down the hill procedure again, and turned it around and finally got up the hill to my town. After hitting flat land it went down to 203 and to 198 fairly quickly. The Question.. Do these fans offer enough cooling power?? they are rated at 4500 cfm a minute. As far as I can tell the standard flex fan rated at around 3500.. Do you think I have another problem going on, or is it just a fact that these electric fans really aren't enough to handle 100 degree heat, a 383 with a 700r4 tranny in a 4x4? Not to mention if I start towing something. Please,, Any experience would be greatly appreciated.. I have the same heavy duty 4 core radiator I had with my previous 383. Been rotted out and cleaned. New high flow water pump. No air bubbles in the system as far as I can tell. could it be because of the New engine running hot?? It just seems like I never had heating problems the last time I did this.. Would a few degrees advanced more then needed cause the problem??? thank you very much for your replys, suggestions and or help.. Barry