1966 BB Fan Shroud Configuration

[Ronald L.]

I have looked at a stack of at least 10 old 66-67 427 BB fan shrouds to repair mine, essentially.

Some have the hole in the upper left side, many do not. Some have also said some part of this 3-piece asy was the same as SB but in the AIM, all three part numbers are different between the two engine size.

What is correct? Hole no hole or there was a change mid year?

thanks,

[Wayne W.]

Re: 1966 BB Fan Shroud Configuration

I have looked at a stack of at least 10 old 66-67 427 BB fan shrouds to repair mine, essentially.

Some have the hole in the upper left side, many do not. Some have also said some part of this 3-piece asy was the same as SB but in the AIM, all three part numbers are different between the two engine size.

What is correct? Hole no hole or there was a change mid year?

thanks,

Cant tell you for sure about the hole cut out. I have also seen both on what I think are original shrouds.

For sure no SB parts are interchangeable with the BB.

[Ronald L.]

Re: 1966 BB Fan Shroud Configuration - what is NCRS Correct?

While this started with simple focus on the hole, which is answered (it is supposed to be there), I am now seeing two more differences between old parts (NOS), perhaps an original part, and the reproductions being sold as "correct" and even differences to those that are hand layup.


Best is to look at the notes on the two posted pictures.

The shroud I have---

1. Has part numbers molded into the Upper and Right side - that MATCH the part numbers in the 66 AIM---

2. Have the DS the judges are looking for on each side R & L---

The two differences to those parts being sold as "correct" are:

1. The RHS "ANGLE CUT-OFF"

2. Each mounting surface is notched out between the attaching clips.

I have looked at many service replacement parts that have "newer" part numbers, 393xxxxxx versus the 1966 38xxxxx part numbers molded into the part and these RS parts were molded by General Tire who was one of the key molders in the 1970's & 80's and those parts have the angle cut off.

It is only on a obvious un numbered reproduction part that the RHS is cut straight across.

So I am looking for the real story (if any one knows) about the notches and the angled cut off.

Prints, part numbers, and revision levels sure would be great because part numbers that match the AIM (in my book) count more the incorrect part numbers or un numbered parts.

Help please.

[Wayne W.]

Re: 1966 BB Fan Shroud Configuration

The one with the angle cut is considered a later production `68, and later over the counter, however, I have seen them on later 67s. It is difficult to determine just when the change occurred, or if those on the 67s are original to the car.

[Ronald L.]

Re: 1966 BB Fan Shroud Configuration

Hi Wayne,


How about the notched out flanges?


Tomorrow I can post the part numbers but I expect these 39xxxxx parts would be a 68 or later release based upon the number.

The question is with the original part numbers for 66 on the shroud molded by the accepted DS molder, did the change for either the notched or angle cut occur in the 66 model year?

[Wayne W.]

Re: 1966 BB Fan Shroud Configuration

Hi Wayne,


How about the notched out flanges?


Tomorrow I can post the part numbers but I expect these 39xxxxx parts would be a 68 or later release based upon the number.

The question is with the original part numbers for 66 on the shroud molded by the accepted DS molder, did the change for either the notched or angle cut occur in the 66 model year?

Cant tell you. I will look on a couple around here tomorrow.

In the mean time here it is on a 68. Note the angle cut and no hole on the left. Small Block with AC BTW.

[Ronald L.]

Re: 1966 BB Fan Shroud Configuration

In looking at a vintage parts book, the assembly for 66 - 68 427 was 3938940. That asy is composed of R/L sides that carry 39xxxxxx part numbers molded into the two pieces.

Does someone have the component PN detail from 67 AIM?

[Wayne W.]

Re: 1966 BB Fan Shroud Configuration

In looking at a vintage parts book, the assembly for 66 - 68 427 was 3938940. That asy is composed of R/L sides that carry 39xxxxxx part numbers molded into the two pieces.

Does someone have the component PN detail from 67 AIM?

I don't have my 67 AIM here, but, I can tell you that if there was a change to the angled RH side, it wasn't in 66.

[Mike M.]

Re: 1966 BB Fan Shroud Configuration

Guys...
The '67 AIM shows PN 3888269 - Upper.
3911110 - R. H.
3886887 - L. H.
On '67's there should be three "DS" Stickers, L, R, Inside Center.
PS: I haven't seen any mention of the '66 "Factory Fix"; that is, the "single flat head rivet in the upper left-hand joint".
HaND

[Ronald L.]

Re: 1966 BB Fan Shroud Configuration

Thanks Mike, I have now seen and verified the 67 version, still not clear on when the cut and notches went into effect.

And the rivet? Tell me more...

[Mike M.]

Re: 1966 BB Fan Shroud Configuration

Ronald, in addition to the "Fix" reference the '66 JG pg. 162, end of paragraph three states:
"The passenger side of the shroud is straight accross, not cut at an angle as with later models".
HaND

[Ronald L.]

Re: 1966 BB Fan Shroud Configuration

Mike, thanks for bringing this up referencing the JG. Does anyone know when this fix was implemented and was it 100%?

One of my 8 data point shrouds has an "owners" fix in this area.

What does the 1967 judging guide say about the big block shrouds?


How about the notches, are they mentioned for the 67?

Again from looking at parts stuck in a warehouse for decades, the notch and angle would seem to go together and both are on a shroud with 100% 1967 AIM matching part numbers & DS logos.

This seemingly 1967 example of the shroud would not have been the service part one year later - 1968 - when both sides of the shroud had part number changes. That part became the service part 3938940. And on the 1968 & up parts (old & never installed) there are plenty of subtleties that differentiate them from the 66 67 question at hand....

[Wayne W.]

Re: 1966 BB Fan Shroud Configuration

I have never considered the "fix" to be 100%. I have seen many shrouds with a factory fix over the years, both SB and BB. It appears to be a random thing to me.

[Mike M.]

Re: 1966 BB Fan Shroud Configuration

Ronald,
the '67 JG makes no mention of these two configuration issues, cuts or notches.
HaND

[Ronald L.]

Re: 1966 BB Fan Shroud Configuration

Mike,

What do you "think" a 67 part should look like?
Notches and angle or neither?


p.s. it is hard to argue with a part in hand that has the DS logos, and all three 1967 AIM part numbers all molded into the parts in clear sight...