1970 a/c with 5 blade fan original ?

**Patrick H.** · November 1, 2021, 11:20 AM

Re: 1970 a/c with 5 blade fan original ?

You can present it any way you want for judging - it's your car after all.
However, the judges have to judge what they see, and whether or not it is "typical factory production."
Also, unless you know the car's history since Day 1, who knows what happened 40 years ago and therefore "looks old."

**Gary B.** · November 1, 2021, 07:21 PM

Re: 1970 a/c with 5 blade fan original ?

I'd like to ask you to keep the fan on the car. In the 68-69 TIM&JG we comment about the fan. We say...

Air-conditioned cars have been seen with five blade fans, but they have a greater pitch to the blades than non-air conditioned cars. Neither style five-blade fan has been seen with a date code.

I am not convinced that practice did not continue through part of 1970. Base motor cars with AC did not have the cooling problems that 350hp and 454 cars did. Any stamps at all on it? Near the mounting bolts? On any of the reinforcements?

Inquiring minds need to know....

Gary B

**Patrick H.** · November 1, 2021, 07:26 PM

Re: 1970 a/c with 5 blade fan original ?

Gary,

Does the 1969 AIM ever call out a 5 blade fan of any type with AC?

PH

**Bob B.** · November 1, 2021, 09:27 PM

Re: 1970 a/c with 5 blade fan original ?

Gary, Thanks for the heads up re my fan, no part number or date only marking is FRONT and 66 or 99 depending on how you look at it probably 99 4 bolt holes This is a Florida 1 owner car, lady owner since new lots of documents I bought a couple years ago.
The 5 blade stays on !!! Bob

**Jeffrey S.** · November 2, 2021, 08:27 AM

Re: 1970 a/c with 5 blade fan original ?

The '69 AIM lists the fan as "Production part" (UPC C60 sheet C1) on base engine. For 427 engine it lists part number 3955182 and shows a 7 blade fan. No alternative is listed. To confirm this, my '69 base engine A/C car has its original fan and it is a 5 blade.
Jeff

**Gary B.** · November 2, 2021, 09:03 AM

Re: 1970 a/c with 5 blade fan original ?

Do I think 69 stuff carried over though part of 70? Yes. Force of habit on the assembly line. People are creatures of habit.

70 UPC 6, Sht A4 (Released 3-28-69) lists a 3888366 fan for the 350 base motor. The drawing shows a 5-blade fan. The 66 stamped on the fan is the last 2-numbers of the part number. It happens to be the same fan also used in 1969 L89 motors, and it cooled them (well maybe most of the time)
70 UPC C60, Sht C1 shows a 3955182 Fan, which is a 7-blade for "350" Engine. The sheet was released in 3-27-69, see any resemblence???
70 AIM, Sheet UPC C60 Sht C2 is for "454" Engines, drawing show's a 7-blade fan, and lists 3993889, which is a 7-blade.

Patrick, you asked about 1969 AIM.
69 UPC 6, Sht A4 (Released 3-28-69) lists a 3888366 fan for the 350 base motor.
69 UPC C60, Sht C1 says "Production Part" for the Fan for "350" Engine. The drawing shows a 5-blade fan, and the Production Part was a 5-blade fan.
69 UPC C60, Sht C2 show 3955182 for "427 engines. The sheet was released in 4-10-68, well into 68 production. It's a 7-Blade fan and the drawing shows a 7-blade fan.

If the car was mine, I'd leave it alone. We learn from these kind of cars, it makes the TIM&JG's better.

Gary B

**James G.** · November 2, 2021, 12:20 PM

Re: 1970 a/c with 5 blade fan original ?

Thanks GARY. You are so correct.

**Bob B.** · November 3, 2021, 05:28 PM

Re: 1970 a/c with 5 blade fan original ?

I think I found the final answer, YES it appears that 5 blade is the original fan blade. I got around to reading our summer '21 issue of Corvette Restorer and there is a extensive article by Joe Tripoli about 53-82 radiator fans, page 13 " Of interesting note is the #3888366 fan, which is used in various years for big block and small blocks with and without A/C. The noteworthy point is this particular fan has FRONT, H and 66 stamped on the front spider. There is a theory that the 66 is the last 2 digits of the GM part # 3888366. I have not been able to verify this but it seems logical"
It should be noted that there are original examples out there that conflict with what is written here. My advise to all would be; If you believe your fan and fan clutch to be original to the car, do not change it to comply with conventional wisdom.
SO, MY FIVE BLADE STAYS !!! FRONT , H AND 66 ARE THERE, no part number or date 70 SB a/c
Thanks all your help on this Bob

**Clark E.** · November 20, 2021, 11:40 AM

Re: 1970 a/c with 5 blade fan original ?

Hi Bob...Just seeing your post. I have a 1970 C-60 roadster 350/300 owned since 1974 that also has a 5 blade fan. Interestingly, the vin is 407561 with a March 23, 1970 build date same as yours. It is stamped with an "H" and "66" on the spider for part # 3888366 which was the standard fan for a non- C-60 vehicle. When beginning a frame-off restoration started in 2011, I've posted several times since regarding the this issue. One of those posts was addressed to '70 C-60 owners with then same issue and I received 2 responses that had the same 5 blade fan.
The JM does not recognize the 5 blade fan for C-60 equipped cars. With dozens of responses to the Forum posts, the consensus was "yes it's possible there was an assembly line substitution, but no way to confirm it actually occurred". I think now with evidence there were 2 vehicles produced on the same day with this part, there is compelling evidence the 5 blade fan was factory installed. My 5 blade is also staying on the car. Clark

**Bob B.** · November 20, 2021, 02:07 PM

Re: 1970 a/c with 5 blade fan original ?

Clark, I appreciate your reply, funny same day production both cars , mine appears to be built earlier in the day. YES, it has to be more than a coincidence both our a/c cars has the 5 blade fan- I would anticipate Gary B will make a notation in the next JG revision (7th) that the 5 blade fan
was not a every car deal but at least will qualify as typical factory production" as so many unusual items are. My car #407502 also has the rare 3 piece telescoping antenna, also my 70 ser# 406787 which the JG calls out between vin 7400 and 8400 only what are the chances- does yours have that telescoping antenna ? I have a lumber Crayola number 788 on my radiator fan shroud- does your ? Build number or what ?
The more we know, it seems we find out there is a LOT more we don't know.

**Clark E.** · November 20, 2021, 07:56 PM

Re: 1970 a/c with 5 blade fan original ?

Hi Bob...Great to connect with you especially on this issue of mutual interest. I reached out to Joe Tripoli and we have exchanged several messages over the last 60 days regarding the fan issue. He's been extremely helpful and connected me with a friend of his who has a '70 350/300 w/air that also has a 5 blade fan like ours. We have been leaving messages over the last 3 days but have yet to connect.
My car has a solid antenna, not one that telescopes. That are no numbers on the fan shroud. That's not to say I didn't wash is off cleaning the engine compartment over the last 47 years before realizing the importance of preserving these codes.
Do you have 2 '70s re: serial # 406787?

**Gary B.** · November 20, 2021, 09:17 PM

Re: 1970 a/c with 5 blade fan original ?

I have updated the 70-72 TIM&JG with more text and more pictures of engine fans, numbers on them. Some members have been helpful sending pictures, helping out. A picture is worth a thousand words?
I don't want to post the changes here, until I am sure it's right? Look at more cars.
I can capture a screen print and email it to you, you could proof read it. Critique it? Tell me if I'm full of
Gary Bosselman
gbozz08@gmail.com

**Clark E.** · November 20, 2021, 09:43 PM

Re: 1970 a/c with 5 blade fan original ?

Thanks Gary...Glad to help out. my email is c.erlandson@atlanticbb.net Would think Bob Brewer would like to be involved based on his initial post on this subject...Clark

**Kenneth B.** · November 21, 2021, 10:51 AM

Re: 1970 a/c with 5 blade fan original ?

Originally posted by Bob Brewer (967)

I am restoring vin 407502 march 23, 1970 build really nice air condition auto convertible
The radiator fan is a 5 blade with no date or part number as our judging guide 6th 2019 says is proper
for a NON_Air conditioned car my A/C car SHOULD have a 7 blade per JG strike shortages ???
The 5 blade fan looks original, the car has had no crash damage VERY low mile appears to be factory installed.

SO-- DO I STAY WITH THE 5 BLADE FAN ?? i IMAGINE THAT IS A PRETTY GOOD HIT ON JUDGING POINTS

There are several other items that appear the factory threw on whatever was handy, goofey antenna, wrong carb
300hp air auto pw tilt ps pb yellow/ black vinyl original

Thanks,
Bob

BOB
Dose your Corvette have a 3 mast antenna with a rectangle knob on top. What is the VIN? My 70 454 came with the funky one also. Its even in the NCRS Guide.

1970 a/c with 5 blade fan original ?

1970 a/c with 5 blade fan original ?

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