Weekly Fun Question - Test Your 71-73 Mustang Knowledge

In a continuing effort to highlights some of the differences between the '71 - '73 mustangs, I am focusing this week's question on the front of the engines, specifically the fans. Question for this week is:

What was the one glaring difference between the fans offered on the '71 and '73 mustangs that was not offered on the '72?




Lets see who will be the first to accurately respond to this question.

BT

I am going to guess. I own two 73's and one 71 so I can;t go look but I will say an flex fan?

I will take a guess too, how about a fan clutch?

this is interesting it sparked me to look at my manuals, i went through the part numbers listed for the fans, 2 things that stood out to me was no mention of a fan clutch in 72 on a mustang, it was on other cars if they had A/C but the mustang listed the same 18.5" fan for both the A/C and non a/c cars.

i saw flex fans being used according to the book in 72.

the only option i didn't see for 72 was the use of 19.5" blades but i believe that was only on the CJ cars.

now i did see use of a 6 blade fan but no mention in 72 as the book claimed 5 fan blades and 7 on the I6 cars.

so i'm interesting in knowing the answer.

my car has no clutch its a 72 a/c car with a 5 blade flex fan.

Well, it appears that I may have finally "stumped" you guys but I have to admit that it took some real effort on my part.

In 1971, there was a 7-blade fan available for the Mustang from the Factory. While this option was not available in 1972, it was a dealer-installed option in 1973.

The 4-blade, 5-blade and 7-blade fans were all used in 1971.

In 1972, 4-blade and 5-blade fans were used on the 250 and the 302. The 2BC non air conditioned 351 generally got the 4-blade while the air conditioned and the 351 4V received the 5-blade fan.

For 1973, the fans were the same as in 1972 except the 7-blade fan was a dealer installed option for the 302 and 351.

Source: 44th Auto-Truck Interchange Edition, The Hollander

Additional Note: According to the manual, clutch fans were never an option on the '71 - '73 mustangs.

That having been said, I am using a 7-blade clutch fan that I pulled (along with the 429 motor) from a '70 Galaxie in my '73 Grande. That puppy really keeps it cool - - I am also using a shroud.

BT

interesting thanks for the info .

i admit i was a little soft on fan clutch information so i looked it up, i wonder why they didn't offer it in the mustangs?

Yes, that is another one of those "strange" things that Ford/Lincoln/Mercury seemed to sometimes do to keep "us" confused.

It is a pretty well accepted fact that clutch fans are better for not using power.

Another interesting thing is that clutch fans were used on the '68, '69 and '70 six cylinder mustangs; the '67 and '68 289s mustangs; the '68 302s; and all the FE big blocks (390, 427 and 428) mustangs from 1968 - 1970. It appears the 351W and 351C in the mustangs never got a clutch from the factory.

The same information applied to the Cougars and Comets for the time period indicated above.

I guess there could be some sort of pattern here that might answer your question.

BT

And I was just about to say 7 blade fans....

Yes Dave, I figured you guys were getting kind of close and I wanted to have at least one weekly question that stumped everybody.

I don't know what I am going to come up with for next week as it is getting sort of difficult to bring forward lesser known differences between the three model years. Oh well, we will see.

BT

Yes Dave, I figured you guys were getting kind of close and I wanted to have at least one weekly question that stumped everybody.

I don't know what I am going to come up with for next week as it is getting sort of difficult to bring forward lesser known differences between the three model years. Oh well, we will see.

BT

Click to expand...

I am sure you will think of something

Keep 'em coming!

Hello, I have to throw this in the mix.

Out of 80 + 71-3's I have had, I have seen 3 factory fan blades.

4 blade- 6 cyl and 302 with out A/C or HD cooling option. 20 inch rad. 2 core

5 blade- 71-3 F code with A/C or HD cooling option, all H, M, Q, R codes 26 inch rad 2 and 3 core

7 blade 71 429 26 inch rad 3 core

Don