67 Fan Blades

[Donald O.]

I have searched through the 1965-67 AIMs and all agree on the same part number, for all engines (327, 396, and 427), with a/c and without. I have heard of a seven blade fan that was used for those cars that were a/c equipped as a way to alleviate some of the extra heat load on the cooling system at low speeds, but can find no part numbers for such.
Have I been misled....again?

Don

[Larry M.]

Re: 67 Fan Blades

Try 1964............

#5853945........... 7-blade 18 inches Have on my own car (67 w/AC).

Larry

[Stephen L.]

Re: 67 Fan Blades

In my 1967 AIM there are 3 different part #'s for fan blades...
2 are on page UPC C60 C2 #3789562, #3863137, and 1 on page UPC 6 A3 #3770529

I don't know the differences.....

[Ray K.]

Re: 67 Fan Blades

Larry,

I think the part number you mean is #3853943 - 18 " x 7 blades. There is a later part number also - #3955182 - 17.50 " X 7 blades

Ray

[Larry M.]

Re: 67 Fan Blades

Larry,

I think the part number you mean is #3853943 - 18 " x 7 blades. There is a later part number also - #3955182 - 17.50 " X 7 blades

Ray

Ray:

I am sure you are correct........the numbers you provided sound/look better. However, in all fairness, the number I wrote came straight out of the 1963-64 Judging Manual that I have in my office. Oh well............

Larry

[Donald O.]

Re: 67 Fan Blades

Larry,

There is a later part number also - #3955182 - 17.50 " X 7 blades

Ray

Isn't for big blocks?
Would it fit in a SB with a SN fab shroud?

[Ray K.]

Re: 67 Fan Blades

Don,

I am looking at my 1965 Assembly Manual ( AIM ) and on page E257 which is C2 with C60 components. Item number 12 is spec'd for the fan blade, however, they have the part number incorrect. It is listed as Larry described it - Part #5853943 - this is incorrect!!!!! The " correct " part number for the fan blade is #3853943, which is 18" diameter with 7 blades. The illustration in the AIM does not show a 7 blade fan nor does it reference that it has 7 blades. However, the P & A catalog takes us beyond that and it is definitely 7 blades. This should fit in your fan shroud without issue because fan shrouds are the same with or without AC. The other fan blade, #3955182 ( I have on my car ) would also fit and the slightly smaller diameter works well for me.

Ray

[David L.]

Re: 67 Fan Blades

Here is what I have for research on theses fans:

3770529 - 5-blade, 17 1/8" dia., 1 5/8" pitch made by Hayes-Albion, stamped "H" (domed head rivets on 63-64 versions, flat head rivets on 66-67 versions)
3789562 - 5-blade, 18" dia., made by Hayes-Albion, used on 66-67 models with AC, stamped "H" (flat head rivets)
3863137 - 5-blade, 18" dia., made by Schwitzner, used on 66-67 modes with AC, stamped "912239" and "SC" with date code
3872792 - 5 blade, 17" dia., 2 1/8" pitch, used on 65 w/396 models
3853943 - 7-blade, 18" dia., used on 64-65 models with AC (domed rivet heads on early versions, flat rivet head on later versions)
3888366 - 5-blade, 17 1/2" dia., 2 1/4" pitch, used on 66-67 427 models, stamped "66" and "H", made by Hayes-Albion

I have owned all of these fans during the last 40 years except for the 3872792 fan but have since sold all of them except for the 3770529 fan. All of these fans have a 3" bolt circle with a 2 3/8" hole. Hayes-Albion fans are stamped with the letter "H" and usually the word "FRONT" and sometimes the letter "W" on the back side. My original 1966 fan (GM # 3770529) only has "H" on the front and "W" on the back side.

Dave

[Harry S.]

Re: 67 Fan Blades

Here is what I have for research on theses fans:

3770529 - 5-blade, 17 1/8" dia., 1 5/8" pitch made by Hayes-Albion, stamped "H" (domed head rivets on 63-64 versions, flat head rivets on 66-67 versions)
3789562 - 5-blade, 18" dia., made by Hayes-Albion, used on 66-67 models with AC, stamped "H" (flat head rivets)
3863137 - 5-blade, 18" dia., made by Schwitzner, used on 66-67 modes with AC, stamped "912239" and "SC" with date code
3872792 - 5 blade, 17" dia., 2 1/8" pitch, used on 65 w/396 models
3853943 - 7-blade, 18" dia., used on 64-65 models with AC (domed rivet heads on early versions, flat rivet head on later versions)
3888366 - 5-blade, 17 1/2" dia., 2 1/4" pitch, used on 66-67 427 models, stamped "66" and "H", made by Hayes-Albion

I have owned all of these fans during the last 40 years except for the 3872792 fan but have since sold all of them except for the 3770529 fan. All of these fans have a 3" bolt circle with a 2 3/8" hole. Hayes-Albion fans are stamped with the letter "H" and usually the word "FRONT" and sometimes the letter "W" on the back side. My original 1966 fan (GM # 3770529) only has "H" on the front and "W" on the back side.

Dave

Dave has provided many great threads on this now and in the past.

The 63 AIM calls for fan 3789562 with C60. I've never seen that fan on a 63 so I installed 3749576 just to help with the cooling. They are both 18 inch as I recall.

[David L.]

Re: 67 Fan Blades

Harry,
I believe that the AC option was added late during the 63 production. I have never heard of a 18" fan (GM # 3789562) that was actually installed on a 63 Corvette with AC on the production line and have also talked with other 63 owners about this as well.
Based on my research the 3749576 fan is listed for 1958-1963 PASS. w/AC, 1961 PASS w/348, and 1961-1963 PASS. w327 & 409 engines. The 3749576 fan has 5 dome headed rivets per blade while the 3789562 fan only has 4 rivets per plade and they are flat head rivets. I have never seen a 3789562 fan with 4 dome headed rivets per blade.

As per Chevrolet Parts History for service parts GM # 3749576 was replaced with GM # 3789562 in July 1964.

BTW, I still have a 3749576 fan in my collection that I bought at a swap meet many years ago, however, even though it looks like it is in very good condition one of the arms has a slight bend probably from being thrown around in the back of some sellers pick up truck. The general word is that a bent or damaged fan should be trashed and not straighten out or repaired. Have you ever heard of anyone straightening a fan, balancing it, and then actually using it on a car? It's a passenger car fan so is it even worth the effort?
Dave

[Harry S.]

Re: 67 Fan Blades

Harry,
I believe that the AC option was added late during the 63 production. I have never heard of a 18" fan (GM # 3789562) that was actually installed on a 63 Corvette with AC on the production line and have also talked with other 63 owners about this as well.
Based on my research the 3749576 fan is listed for 1958-1963 PASS. w/AC, 1961 PASS w/348, and 1961-1963 PASS. w327 & 409 engines. The 3749576 fan has 5 dome headed rivets per blade while the 3789562 fan only has 4 rivets per plade and they are flat head rivets. I have never seen a 3789562 fan with 4 dome headed rivets per blade.

As per Chevrolet Parts History for service parts GM # 3749576 was replaced with GM # 3789562 in July 1964.

BTW, I still have a 3749576 fan in my collection that I bought at a swap meet many years ago, however, even though it looks like it is in very good condition one of the arms has a slight bend probably from being thrown around in the back of some sellers pick up truck. The general word is that a bent or damaged fan should be trashed and not straighten out or repaired. Have you ever heard of anyone straightening a fan, balancing it, and then actually using it on a car? It's a passenger car fan so is it even worth the effort?
Dave

I agree, a bent fan should not be used. Lots of vibration will probably cause problems.

[Leif A.]

Re: 67 Fan Blades

Harry,
I believe that the AC option was added late during the 63 production. I have never heard of a 18" fan (GM # 3789562) that was actually installed on a 63 Corvette with AC on the production line and have also talked with other 63 owners about this as well.
Based on my research the 3749576 fan is listed for 1958-1963 PASS. w/AC, 1961 PASS w/348, and 1961-1963 PASS. w327 & 409 engines. The 3749576 fan has 5 dome headed rivets per blade while the 3789562 fan only has 4 rivets per plade and they are flat head rivets. I have never seen a 3789562 fan with 4 dome headed rivets per blade.

As per Chevrolet Parts History for service parts GM # 3749576 was replaced with GM # 3789562 in July 1964.

BTW, I still have a 3749576 fan in my collection that I bought at a swap meet many years ago, however, even though it looks like it is in very good condition one of the arms has a slight bend probably from being thrown around in the back of some sellers pick up truck. The general word is that a bent or damaged fan should be trashed and not straighten out or repaired. Have you ever heard of anyone straightening a fan, balancing it, and then actually using it on a car? It's a passenger car fan so is it even worth the effort?
Dave

Dave,
Some clarification if you would, please. Quoting from the 7th edition of the TIM&JG.

"Air conditioned small block fans were either one of two assemblies. Both have five blades with an overall diameter of 18" and use five mushroom head rivets to attach each blade to a reinforcement arm. The arms of the fan assembly part number 3789562 have an elongated triangular shape with the front of the reinforcement having an "H" stamped in the center."

Below are pictures of my fan in my '67 L79 w/C60. Hayes-Albion with five mushroom head rivets. What am I missing?

[David L.]

Re: 67 Fan Blades

Leif,
Attached is a photo of a shop drawing of a 3789562 fan taken from Noland Adam's 63-67 Corvette restoration book, Page 118. Clearly the drawing shows 4 rivets per blade. I trust a GM shop drawing much more than what is written in judging manual written in recent times. I also once owned an original 3789562 fan, 18" did., 5 blades, 4 rivets per blade, stamped "H" and "FRONT" on the front and "W" on the back but sold it long ago. Attached is a photo of a 3789562 fan from the web. These fans are hard to find.

Is your fan original to your 67 w/AC? Dome headed (aka, mushroom) rivets were used on 1958-1963 and maybe even 1964 fans. Flat rivets were used from 1965 and later fans. The 66-67 Corvettes w/AC also were issued the 3863137 5-blade 18" fan stamped "912239", "SC", and a date code. Is this in the 7th edition judging manual? I do not have any judging manuals and never will.

The 18" 5-blade GM # 3749576 fans with 5 rivets per blade are as common as white bread. They were used on 1958-1965 passenger cars w/AC , 348, 327, and 409 engines. I will add a photo of a NOS 3749576 in a later post.
Dave

[David L.]

Re: 67 Fan Blades

Attached are 2 photos of a 18" 5-blade NOS 3749576 fan with 5 rivets per blade. The 3749576 fans made in 1964 may or may not have had flat rivet heads but most of them had dome headed rivets.

[Michael S.]

Re: 67 Fan Blades

i am restoring a 64 coupe with 37k on it. it has been hit in the nose and now has a 66-67 nose. i am not sure if the fan was replaced. so here are some pic's. can some one tell me if they think this fan came on a 64 365 hp non a/c car? i cleaned it up today and it has the h stamp and front stamped into it. nothing on the back side. it measures 18 inchs. thank you. mike.fan 001.JPGfan 004.JPGfan 005.JPG