Which of these fan blade counts did NOT come from the factory on Cougars (years 1967 to 1973)? 4? 5? 6? 7? 8? (Hint: 2 of these should be easy for you!)
What is 8. That’s my final answer. 
John
Correct. As far as I know, a 8 bladed fan was never made/used. 7 blade fans (fixed blades with clutch) were used for several yeras. (C9WY, C9ZE, C80E, etc). 5 blade fans with flex blades and no clutch were also very common. Now, what about 4 or 6 blade fans?
No 6 blade fans. My 69 as a 4. Mike
Yes, to the 6 blade fan. Pretty obscure fan, was used on 1969 428 Super Cobra Jet engines.
So no 4 blade? It was in a box with the stock parts for our M code FMX no AC Eliminator. Was the 6 blade fan a fixed or clutch fan? Our SCJ has a C9ZE-E on it. (3.91 C6 car)
Here’s my 4-blade, before I cleaned it up …
Yes, to the 4 blade fans on 289/302/351’s with standard cooling on many models.
6 blade fan for the 1969 SCJ was a fixed pitch non-clutch fan.
8 blade is the answer.
Duh! I misread the question the first time. I was trying to figure out which 2 were not used. Mike
429CJ 7 Blade flex fan
Courtesy 429CJ Mustang Cougar megasite