im going to swap out my 5 bladed ford flex fan for a stock 7 bladed ford fan with fan clutch. im figuring that it will cool better at idle. anyone done this swap.

 

The cop cars of the late 60's & 70's era that I have seencame with 7-bladed clutch fans that were part of the heavy duty cooling packages.
If the 5 blade flex fan was better, as far as Fords engineers are concerned, then I would think they would have put that on them instead. Swap it out and see whats shakin'. That will be interesting to see if you do indeed notice a difference.

Are you running hot now at idle?

 

well it will get to 200-210. but then its 115-120 temps here and the ac is on. ill be trying it next weekend. cant see where it would hurt.

 

210 is getting a little warm. That is where my "oh poop" alarm starts going off. I wouold appreciate it if you would lett us know the results.

 

I wouldn't waste the time or money. 200-210 is what these old motors are supposed to run at. And, at the outside temps you say you are experiencing, you are running just perfect with the air on.

 

I guess I need to ask, is the 210 the max or does it continue to creep up if left idling?

 

most new cars run aroud 240degrees to reduce emmsisions so theres nothign to worry about 210 is not boiling in a closed system or one with antifreeze because both raise the boiling point

 

However, my car usually runs a 190 come hell or high water. When my temp hits 210 it is time to figure out why the change is happening. 215 I pucker, 220 and I shut it down.

 

I run up to 240 on my '71, depending on what I'm doing. Just idling, I top out around 215. Down the road it'll hang around 185 or so (180 Tstat).

 

If it never boils, don't worry. When you shut it down at 220, do you hear the coolant boiling in the rad? Most likely not because the boiling point is around 240. You are in some damn hot country, and by running the air con, you are going to get up over 190 real fast.