Requesting cooling/radiator/fan help for a slant six

That test is biased to a situation that barely exists. How often will your engine be spinning at redline? And how many of us are running direct drive fans?
And how often will you be running it up to 100mph?
No, if you are a streeter, your run is 1.5 to 2 gears long; from zero to 60 and then you are done.So you will hit redline probably just once with that super-wide-ratio box. It would take at least 3.73s to hit redline twice.
Put a thermostatic fan clutch on it and call it done;
Or, on a slanty which barely makes any heat in the first place, you can get away with a viscous clutch.
As you may know, the viscous coupler allows the fan to lag behind the coupler quite a bit, and during a WOT run it will never reach pulley speed. I wonder if it would even reach 50%. So the power loss is minimal. But you can prove it; stick it in second gear and make a run from say 2500 to 5000 and time it. Take a best of 3. Then take the fan off and repeat. Run the car at 25mph to cool it off if the temp starts to rise. Let us know what you discover,
I cool my 225 with a 4 blade direct-drive low attack-angle fan, a teensey rad, and no shroud at all.This engine is only warmed a little with 9.5 SCr and a small cam.
Good luck.