'69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

[Steven B.]

I'm doing some restoration on my '69 and have a radiator that is not original but keeps the water temp low (according to the dash gauge). I assume the fan is not original too as it's a 5 blade. In reading the manual, it says the car should have a 7-blade fan with a/c. Is there any reason to change this to a 7-blade? I know the odds of finding a 7 blade with the proper date coding is one in a million, but will it operate better with the 7? Any reason to change? As I said the water temp never rises and the car can sit idling for 30 min without ever raising the temp. Leaving well enough alone sounds like a plan but wanted to hear expert give their thoughts!

Thanks, Steven Berson

[Stephen L.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

Comes under "if it ain't broke don't fix it" If you plan on getting it judged, keep an eye out for a "correct" fan. In the meantime enjoy the car.

[Steven B.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

My feelings too, thanks Stephen.

[Joe L.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

I'm doing some restoration on my '69 and have a radiator that is not original but keeps the water temp low (according to the dash gauge). I assume the fan is not original too as it's a 5 blade. In reading the manual, it says the car should have a 7-blade fan with a/c. Is there any reason to change this to a 7-blade? I know the odds of finding a 7 blade with the proper date coding is one in a million, but will it operate better with the 7? Any reason to change? As I said the water temp never rises and the car can sit idling for 30 min without ever raising the temp. Leaving well enough alone sounds like a plan but wanted to hear expert give their thoughts!

Thanks, Steven Berson

Steven-------

First of all, I'm not so sure that all 1969 small blocks with C-60 were originally equipped with a 7 blade fan. I could easily see the 5 blade GM #3888366 being installed on the assembly line. If your 5 blade fan is a GM #3888366, I'd be willing to bet it's original to the car. How can you tell if it's this fan? Well, with the fan installed on the car, it's difficult unless you are really familiar with the configuration of that fan. However, off the car it's easy. The center section of the blade assembly is stamped "66".

Second, if it is 3888366 it's probably worth more than the 7 blade GM #3955182. That's because the 3888366 was also originally used on many 1966-69 Corvette big blocks. Also, the 3888366 is not dated so any example is correct for a car that originally used one.

As far as cooling efficiency goes, my experience says that there is no real significant difference between the two fans. Why do I say this? Well, my original owner 1969 300HP had cooling problems from day-one. A year or two afterwards I decided to try replacing the original 3888366 with the 3955182 to improve cooling. This change made no difference, at all, at least no perceptible difference.

[Jeffrey S.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

Steven,
Joe is absolutely correct (what's new about that) that not all '69's with A/C had 7 blade fans. My Oct. '68 with A/C has the original 5 blade fan installed.
Jeff

[Steven B.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

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Joe, thanks for that very helpful info. I happened to find three photos, one of each side of the fan when it was removed a few months ago and the clutch. I've enlarged it to try and see the "66" stamp, but don't see it, although the fan clutch is blocking me seeing the center of the fan There is a "Canada Patent pend. 1961" on the left side of the clutch and "patented other pat's Pend" on the right side edge of the clutch. One blade has a "W" embossed into it. Not sure if any of the info or photos helps but thats what I've got.
Steven

[Steven B.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

Thank you Jeff, that's great info and makes me think this fan is original. I've posted what I can on mine so now I'll just leave it alone and "assume"
it's original. No reason to think it isn't, as most of the car is numbers matching except the radiator and brake cylinder. This car is a Dec. '68.

[Joe L.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

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Joe, thanks for that very helpful info. I happened to find three photos, one of each side of the fan when it was removed a few months ago and the clutch. I've enlarged it to try and see the "66" stamp, but don't see it, although the fan clutch is blocking me seeing the center of the fan There is a "Canada Patent pend. 1961" on the left side of the clutch and "patented other pat's Pend" on the right side edge of the clutch. One blade has a "W" embossed into it. Not sure if any of the info or photos helps but thats what I've got.
Steven

Steven------


I am familiar with the configuration of the 3888366 and I'm virtually certain that's what your fan is. The "66" stamping will be on the side of the fan concealed by the fan clutch.

The fan clutch also appears to be original. It's a GM #3937771, just as it should be.

[Steven B.]

Re: '69 350/350 manual A/C with 5 blade fan-Any reason to change to 7?

Thank you Joe, that makes me feel good about both parts. The AIM does say some '69 A/C cars do have the 5 blade, but I just assumed mine was changed at some point. Now I know better. Once again, your knowledge, wisdom and passion for these cars is second to none. Thank you!!!!