"Tailfins and Bowties" book

[442w30]

For years I've been looking for this book. I know at least one member here has it, but it's been elusive on eBay or anywhere else.

But I finally found a copy, as a friend bought a literature collection from an estate. It wasn't cheap, but it's nice to have a compendium of Chevy data (even if a small portion of it has been published in several books).

As an aside, I know a library in the South had a copy, and I told my contact at the GM Heritage Center. Libraries loan things to other libraries, so he was able to score the book and compare it to the Chevy records that the GMHC has. He told me there were some things in the book that were not in the GMHC's records, so it was nice to help him upgrade the level of info available. Not sure where exactly the data from the book came from other than it's from Chevrolet.

[Kurt S]

Len published the data from GM documents. He actually just reprinted most of the documents.

[442w30]

Yeah, but they're different documents than what are currently held by the GMHC. A very large percentage is overlap, but they are two distinct items from what I can gather. I can only guess they each were for different departments.

[Kurt S]

GMHC told me they were the same.....

[442w30]

That's not what my contact told me –*he said there was some new info that weren't in GMHC records, but not much.

[Kurt S]

I'll ask Christo again next time I'm there.

[442w30]

Ha! He's my contact too!

[Keith Seymore]

Ha! He's my contact too!

Me three!!

(I think he probably gets tired of me asking him weird stuff).

K

[Verne_Frantz]

Len sold the book(s) based on how many years you were interested in, and priced differently. Mine is just '58-'65. How many years does the complete work include?

I also tried to contact Len a few months ago but never heard anything. I'm wondering if he's still with us?

Verne

[442w30]

Mine goes up to 1978, but I think I've read that it goes up to 1988 from what I read? Hmmm...

[Kurt S]

Len died several years ago in a freak car accident.

[MrLenny]

Len Williamson was my dad. He and my uncle drove from Oklahoma to Detroit, Michigan in the late 80s and made copies of all of the records that Chevrolet had with their permission.
The first set of 2 volumes contained production numbers and options for all passenger vehicles from 1953-1988. He was sent annual updates until 1993 and Chevrolet stopped sending the data. He didn't get rich by any means by selling these books. He just wanted to share the information.

[442w30]

This is pretty cool.....is there a way for us to fill in the gaps of the info we've collected? I have the book but not the complete volumes, as I think mine goes up to 1978 or so.

[Nasblu]

Len Williamson was my dad. He and my uncle drove from Oklahoma to Detroit, Michigan in the late 80s and made copies of all of the records that Chevrolet had with their permission.
The first set of 2 volumes contained production numbers and options for all passenger vehicles from 1953-1988. He was sent annual updates until 1993 and Chevrolet stopped sending the data. He didn't get rich by any means by selling these books. He just wanted to share the information.

Do you have any copies forsale or the means to reproduce these books to sell them again??

[L72copocamaro]

Do you have any copies forsale or the means to reproduce these books to sell them again??

If so, they would be in High Demand!

[Kurt S]

Not sure why a book with the production numbers would be in high demand. GM still has these records. And over the years, the numbers have been published in many forms by many people.
The unique aspect to this book is the pages are copies of the originals directly from GM (and it was one of the first to publish these numbers).

Lenny,
So sorry to hear about your father's accident.

[70 copo]

Len Williamson was my dad. He and my uncle drove from Oklahoma to Detroit, Michigan in the late 80s and made copies of all of the records that Chevrolet had with their permission.
The first set of 2 volumes contained production numbers and options for all passenger vehicles from 1953-1988. He was sent annual updates until 1993 and Chevrolet stopped sending the data. He didn't get rich by any means by selling these books. He just wanted to share the information.

Len was one of the early research pioneers that established a collaborative relationship with GM and his book Tailfins and Bowties is a masterpiece to this day.:flag:

[Tarrytown SS427s]

I borrowed the full volume through inter-library loan when I was in college 10 years ago. I was pretty excited to look through it, but I didn’t find much data that wasn’t already widely known. The ECL production trends book offers a much more detailed look at production totals, though a lot of it is hard to understand without an understanding of the ECL codes, and some of the years/models went missing at some point..

[Verne_Frantz]

Steve,
Could you explain a little more about that ECL production trends book you mentioned? I'm not aware of it. It might help me with the research I'm doing now.



Verne

[442w30]

Steve filled me in on the ECL code thing. I asked my contact at the GM Heritage Center if he had heard of such a document, which he hadn't, but he found something that may be it. So when I was in MI in my yearly pilgrimage to the Pure Stock Drags, I stopped by to check out the docs. Yes, this stuff will fill in the blanks for some info that Chevy people are dying to know, but it all needs translating. For some stats, they may correspond to a body code (like L78 Caprices: https://impalas.org/1965caprice/) which makes things easier.

I'm sure Steve can explain it even better.

[Verne_Frantz]

Yes, I am aware of a GM publication that lists option totals that uses letter codes to indicate models, but it has no cross reference between those letters and the models they represent, so in many cases, the totals include various models if the same option was available on them. Some of them may also be ECLs, but that is unclear.


ECL codes themselves corollate to a parts list for that option. For instance, an interior trim code option would have different ECL codes for door panels for crank windows vs power windows.


Verne

[442w30]

The GMHC doesn't have a key for translation, AFAIK. Maybe that's the next step of the hunt.

[Verne_Frantz]

I need to talk to Christo about something else but I doubt he's in the office these days.


Verne

[jeffschevelle]

I have seen small bits of the book with the ECL breakdowns, and for some options and some years it actually does identify exactly what models each ECL applies to. For example, 67 Chevelle L78 production (total 612) is shown with two ECL's split between 13817-67 [SS Coupes and SS Convertibles] (578 units) and 13480-680 [Elcamino and Elcamino Custom] (34 units). That's how we knew exactly how many L78 Elc's were built like the one I had at MCACN last year. (Although I screwed up and put 35 on the sign!!)

For the options that have several ECL's listed but do not tell you what each one applied to, understanding why there would be a different ECL code in the first place is the key to deciphering all that data I think. For example, why were there two 67 Chevelle L78 ECL's? Why not one? Why not four? The reason is that (as I understand it) each ECL represents a parts list of every part that had to be added or changed for a given option, OR it can represent a different price for the same option when coupled with other different equipment. With that understanding, it is easy to see why there were two 67 Chevelle L78 ECL's:

To put an L78 in an SS coupe or SS convertible required exactly the same parts, and the option was the same price. All SS's already came standard with 396/325 engines, HD floor shifted 3-spds, 12-bolt rear axles, big block springs, and big fuel lines and sending units. So adding an L78 to EITHER of those cars involved only the engine, carb, air cleaner, fuel pump, DG pulleys, clutch fan, and 4-row radiator. There would be no reason to have a different ECL for an SS convertible L78 because the parts list and price were exactly the same as an SS coupe L78.

But the Elcamino models had to have a different ECL because a lot more had to be changed, and the price was higher. Any 13480 or 13680 V8 Elc came standard with a 283 engine, regular column shifted 3-spd, 10-bolt axle, small block Elc springs, single exhaust with small tailpipe, small fuel lines and sending unit, and a small radiator. So putting an L78 in a V8 Elc involved replacing ALL those parts (along with the carb, air cleaner, fuel pump, DG pulleys and clutch fan), and the engine upgrade cost was to go from 283 to 396/375 (rather than from 396/325 to 396/375). But there would be no difference at all between upgrading a 13480 Elc and upgrading a 13680 Elc; therefore only one ECL was needed for both Elc models.

Then take by contrast an L79 in a 67 Chevelle. That was not available in an SS so any L79 upgrade started from a standard 283 V8 spec car. So you might think there would only be one ECL for an L79. But there actually should be at least 8 different ECL's for that. The variables are:

- Small clutch L79, versus HD clutch L79 (the engine was a different part number for the HD clutch)

- Coupe/Sedan/Wagon 5/16 fuel line (for open frame rail), versus Convertible/Elc 5/16 fuel line (for boxed frame rail).

- Coupe/Sedan/Convertible fuel tank with 5/16 sending unit (the tank and sender were an "assembly" part number in the plant), versus Wagon/Elc fuel tank with 5/16 sending unit.

So, 2 x 2 x 2 = 8 possible combinations of 67 Chevelle L79 parts, depending on body style and clutch. So there should be at least 8 ECL's, for:

1. L79 in a Coupe or Sedan with std clutch
2. L79 in a Coupe or Sedan with HD clutch
3. L79 in a Convertible with std clutch
4. L79 in a Convertible with HD clutch
5. L79 in a Wagon with std clutch
6. L79 in a Wagon with HD clutch
7. L79 in an Elcamino with std clutch
8. L79 in an Elcamino with HD clutch

***
This is all fascinating stuff to me, and I REALLY wish I had a copy of that ECL production book because I am pretty sure I could figure it all out given a little time, and pics of a bunch of original window stickers!!

[Xplantdad]

Amazing info Jeff....thanks for taking the time to post it! :worship:

[442w30]

- Small clutch L79, versus HD clutch L79 (the engine was a different part number for the HD clutch)

- Coupe/Sedan/Wagon 5/16 fuel line (for open frame rail), versus Convertible/Elc 5/16 fuel line (for boxed frame rail).

- Coupe/Sedan/Convertible fuel tank with 5/16 sending unit (the tank and sender were an "assembly" part number in the plant), versus Wagon/Elc fuel tank with 5/16 sending unit.

So, 2 x 2 x 2 = 8 possible combinations of 67 Chevelle L79 parts, depending on body style and clutch. So there should be at least 8 ECL's, for:

1. L79 in a Coupe or Sedan with std clutch
2. L79 in a Coupe or Sedan with HD clutch
3. L79 in a Convertible with std clutch
4. L79 in a Convertible with HD clutch
5. L79 in a Wagon with std clutch
6. L79 in a Wagon with HD clutch
7. L79 in an Elcamino with std clutch
8. L79 in an Elcamino with HD clutch


That's quite an interesting explanation. The only explanation I've seen otherwise, aside of those cars with VIN prefixes, is regarding equipment for the 1967 Z/28 (standard, cowl induction, headers, and both of the latter).

So if you see this key I'm attaching, do you think you can nip and tuck your list above?

[jeffschevelle]

That's quite an interesting explanation. The only explanation I've seen otherwise, aside of those cars with VIN prefixes, is regarding equipment for the 1967 Z/28 (standard, cowl induction, headers, and both of the latter).

So if you see this key I'm attaching, do you think you can nip and tuck your list above?

What year is that table from? I'm a million miles from being a Camaro expert, and even farther away if it is after 67. But I thought the 67 Z28 window sticker codes were BA, BB, BC and BD?

[442w30]

Those are 1967 A-body ECL codes for L79.

[jeffschevelle]

Those are 1967 A-body ECL codes for L79.

Oh, OK. You mentioned Z28 right before that so I thought that's what that list was supposed to be for. I'll study on it some now that I understand the question! Thanks

[442w30]

Anyway, you can see 7 different segments for 9 different codes. Doesn't match your 8 segments but maybe we can figure this out?

[jeffschevelle]

442W30 -- Could you send me some additional info -

1. Could you email me a bigger pic of the 67 Chevelle L79 section including the quantities for each code? Seeing which ones are higher quantities versus lower does not prove anything, but it would be at least a suggestion of which codes are "probably" for a coupe.

I am also thinking that A.I.R. smog may have something to do with it, since a smog engine would have a different part number than a non smog. Seeing the quantities might reveal that adding certain codes together equals the total number of smog L79 engines built (if I can find that production total data in the giant piles of stuff I have here).

And it would also help to see if any of these L79 codes are listed with a 0 quantity. If so, it blows up the idea in #2 and #3 below. But if none show a 0 quantity, then below are viable ideas.

2. Do any of the codes listed for other options show that they used the letters E and F in the second slot of a code? I note that this 67 Chevelle L79 list jumps from AD to AG and skips over AE and AF. If E and F are used in the second slot of some other codes, then that would suggest there are at least two more 67 Chevelle L79 codes that are not listed, due to 0 quantity built.

3. Do any of the codes listed for other options show that they used the letter I in the second slot of a code? This list also skips over AI, so same analysis as #2 above. But I could see them deliberately skipping over the letter I to avoid confusion with the number 1.

4. What are the L79 ECL's listed for 67 Vettes and Novas? Do they start with AA too, or are they a separate list from the Chevelle codes with no overlap? If there is no overlap, then knowing what the Vette and Nova codes are might tell us which codes are "missing" from the Chevelle list due to 0 quantity (if that is the case).

5. Do any of the other options list BOTH the ECL AND the corresponding body style? If so, can you see any pattern of a "standard order" for listing body styles in a certain order within the ECL code lists (when body style matters)? For example, is AA always a coupe? Or always a 4-dr sedan?

If smog is factored in, then we go up to 12 total 67 Chevelle L79 codes rather than 8:

1. Coupe/sedan L79
2. Coupe/sedan L79 w/ HD clutch
3. Coupe/sedan L79 w/ AIR (note that HD clutch was not available with AIR for some reason, so AIR does not double the previous 8 total I hypothesized)

4. Convertible L79
5. Convertible L79 w/ HD clutch
6. Convertible L79 w/ AIR

7. Wagon L79
8. Wagon L79 w/ HD clutch
9. Wagon L79 w/ AIR

10. Elc L79
11. Elc L79 w/ HD clutch
12. Elc L79 w/ AIR

Then, if three of those combos had 0 produced (provided that none of the codes that ARE listed shows a zero), then there's your 9 listed codes out of 12 total possibilities. Figuring out which ones were a zero is another matter, though.

I found a pic of one window sticker for a 67 Malibu L79 coupe with std clutch and no AIR that shows AH code. Don't know if it is a real w/s though.

This is fun, ain't it? Thanks!

[TAR6569]

Sent you a PM Jeff. It's tons of fun!

[442w30]

Jeff, Warren is in touch I believe.

[396guy]

Len Williamson was my dad. He and my uncle drove from Oklahoma to Detroit, Michigan in the late 80s and made copies of all of the records that Chevrolet had with their permission.
The first set of 2 volumes contained production numbers and options for all passenger vehicles from 1953-1988. He was sent annual updates until 1993 and Chevrolet stopped sending the data. He didn't get rich by any means by selling these books. He just wanted to share the information.
I make a number of Chevelle-related CDs and DVDs. Would you be interested in allowing me to take the copy I have and put it into program form on a CD? I'll do all the programming work to make it easy to follow.
Regards...