Understanding Common Date Coding Systems for Mid 60’s-early 70’s GM cars

Discussion in 'The Bench' started by Duane, Aug 7, 2018.

  1. Duane

    Duane Member

    There seems to be some interest about this book lately so I decided to make a post to keep everthing in one place. If you are interested in purchasing one please post it here.

    For those that do not know I wrote a reference book about date coding systems for mid 60’s thru early 70’s GM cars. Below is an excerpt from the book that explains what it covers.

    Mission Statement
    As the interest in vehicles with original or correct components continues to climb, the ability to verify these pieces becomes more and more critical. Most parts, including major drive train components, not only have part numbers stamped or cast into them, but are also date coded. Therefore, an understanding of both part numbers and date codes is needed to verify the “correctness” of these parts for any given vehicle.

    The goal of this Manual is to familiarize the buyer with the various date coding systems used throughout these vehicles. The hope is that this knowledge, combined with a familiarity of part numbers, will give the buyer the ability to accurately determine which parts are correct or incorrect for vehicles built during these years.

    Four major items will be included within this manual;

    1. There will be a discussion regarding the Fisher Body ID Plate, which is the “key” to understanding the correctness of all date coded parts on a vehicle.
    2. There will be photographic examples of each type of date coding system, whether it is cast, incise stamped, ink/paint stamped, or is printed on a tag, and an explanation of how to decode them. (The only exceptions to this will be with the Glass Codes. Due to the difficulty of photographing them, drawings will be used instead of photos.)
    3. Calendars for the years 1964 thru 1972 will be included, listing the day of the month, day of the year, and week of the year, plus a guide explaining their use.
    4. And finally, at the end of this manual, will be a comprehensive list of parts that will reference the types of date codes commonly found on them, and when necessary, the approximate locations where these codes can be found.

    This book will decode Buick, Chevrolet, Oldsmobile and Pontiac date coded parts including; body panels, front end sheet metal, radiator core supports, all makes of glass (LOF, PPG, & DCL), DMI sport mirrors, radiators, all major cast engine components, vacuum trees, oil sending units (at least for the gauge equipped cars), water pumps, valve covers, oil pans, both varieties of clutch fans, Rochester, Holly, & Carter carburetors, starters, distributors, alternators, air cleaners, AC compressors, AC hoses, voltage regulators, steering boxes, master cylinders, power boosters, brake drums, calipers, brake rotors, car frames, front suspension center links, seat belts, radios, seat frames, bucket seat headrests, steering columns, Turbo-Hydramatic auto transmissions, Borg Warner T-10 and Muncie 4-speeds, Ford top-loader and Saginaw 3-speeds, rear axles, rims/wheels, spark plug wires, and probably a hundred other parts I haven't mentioned. (Please note; production codes for engines and transmissions will not be discussed.)

    The cost of the book shipped is $46.00. This includes $40.00 for the book, and $6.00 for shipping anywhere in the continental US. If you are interested in purchasing this book, you can send a check, money order, or do PayPal to,

    Duane Heckman
    120 President Ave.
    Rutledge, Pa. 19070.

    I currently have 8 books in stock and can make more as needed. Below is a pic of the cover of the book.

    Thank you for your time.

    One other thing, If you have a 70-72 car and get one of David's "GS by the Numbers" books then you would know all the date codes and part numbers for your car. Between the two books that should ID almost all the parts for your car.

    Date Code Book Cover.JPG
    Last edited: Aug 7, 2018
  2. thepartsman

    thepartsman Back Ordered Again ?

    Thanks Duane,

    Just a quick note about these books.

    I had several conversations with Duane, Mark Reeves and other restorations shops about the need to find info on each car in one location, mainly a book. In 2009 I had a talk with a retired Buick Tech Supervisor and was told that “new” GM had destroyed the files containing 40 years of cast and stamped ID numbers and how they related to part numbers.

    Therefore these books are based upon info from GM / Buick Motor Division, Service and Parts Bulletins, Parts and Illustration books, Service Manuals, Buick Parts History Books, AC/Delco History Books, what I have seen and noted from original cars and info submitted by you, the GS owner.

    Some of the books are in their 5th printing, another 3rd printing and the new Quick Reference Book is in its 1st printing. All should be back in stock by the 1st or 2nd week of September.
    You can contact me on this board or through Facebook. I take Money Orders and Paypal.

    The books are $55.00 each and the Quick Reference Book is a pocket size book and is $25.00. All carry a $5.00 each shipping charge.

    Also in the back of each book you will find info for ordering the other books plus Duane Heckman’s Book and Correct Hardware kits from Todd Miller’s Diecast Muscle Cars.

    In the pics below I have posted the "70 Content page to give you some reference as to what is contained in each book.

    Thank you, David BTN 70.jpg BTN 71.jpg BTN 72.jpg BTN GSX IMAGE.jpg QRG 65-75.jpg 70 CONTENT 1.jpg 70 CONTENT 2.jpg
    Brett Slater likes this.
  3. Duane

    Duane Member

    There you are guys.
    If you buy both my book and David's book, for the year of your car, you would be able to authenticate all your parts and make sure they are the correct dated pieces for your car.

    It's pretty cool when you start digging into the dates of parts on a specific car. You end up learning a whole new history of the vehicle. It's easy to see which parts are not correct and then tell if the car was in a front-ender, or if a door was replaced, or an interior was swapped out, etc. On a few instances you can tell if the car is what I call a "scatter skeleton", that is where a car came with parts from multiple vehicles.
    Last edited: Aug 11, 2018
  4. woody1640

    woody1640 Well-Known Member

    So any books on the early 6o's date coding?

  5. Duane

    Duane Member

    When you say early 60's, what years are you talking about?
    I made sure I covered the 64-72 GM cars so I titled the book that way, but a lot of the same date coding systems were used many years before that.

    I would have to check the book, but I may not have glass codes for pre-64 cars. Other then that it would probably be good thru the early 60's.

    Most of the systems stayed the same thru to the end of 71 production. It wasn't until the 72 Model year started that things started to change. I had to add quite a few dating systems for the 72 model year, but wanted to include them for obvious reasons. That alone took another couple of weeks to do.
  6. Buickone

    Buickone Founders Club Member

    What's your email to use for PP Duane?
  7. woody1640

    woody1640 Well-Known Member

    When I said early 60's I was thinking exactly that lol. I was thinking 61-63 though.

  8. Duane

    Duane Member

    I think the book would be fine for the 61-63 cars. I know the 59-60 cars used some different date coding systems, so you might have some trouble there.

    The only things my book will not have are the Calendars for the 61-63 production years (They start in January of 1964, which would be the last half of the 63 production year) and the date codes for the LOF glass. The PPG & DCL glass codes might still be OK, but I can't swear to that.

    You would have to develop the calendars, but it would probably not be too hard. I am sure you could find something on line showing each year, and then add the letter codes for the months and label the weeks of the year. You would also have to add the day of the year for some codes.
    Last edited: Aug 9, 2018
  9. Duane

    Duane Member

    I'll make you a deal. If you are interested in the book I will mail one out to you. If you like it and find it useful for your year car, you can keep it and send me $46.00
    If you don't want it, then mail it back and all you are out is the shipping back to me.

    How's that for a deal.

    The year codes for LOF glass are the following
    1960 U
    1961 L
    1962 I
    1963 C

    So now with the book you can figure out your month/year of LOF glass for all the 61-63 cars.
    Last edited: Aug 11, 2018
    1972 Stage 1 likes this.
  10. priariecanary

    priariecanary Stacey

    I'll take one of Duane's books plus David's 1970 book and Quick Reference Guide. PM inbound to both of you.
    thepartsman likes this.
  11. 1967 Big Buick

    1967 Big Buick One day at a time.

    I just found my date code book today. By accident of course. I had it tucked away in safe place for YEARS lol.
  12. #7

    #7 Well-Known Member

    I have used Duane’s book a lot to make sure my car is what i have always believed it to be. His book confirmed everything i looked at. It was a real kick finally understanding what all those markings are. It’s a great tool.
  13. Marcdbuilder

    Marcdbuilder Well-Known Member

    Hello Duane.
    New member. This is my first time doing anything other than eaves dropping. I would like to have a copy of your book when ever it becomes available. Thank you very much for what I can only imagine was an incredible amount of work.
    Best regards, Marc.
  14. Duane

    Duane Member

    They are available now. PM me your name/address etc. and I will get one out for you.

    STAGE III Lost Experimental Block

    How did I miss this thread? I gotta get both these books once I refill my piggy bank!

    I have enough for yours for now Duane, will Pay Pal ya later today. Thank you and David for what must have been an exhaustive feat!
    thepartsman likes this.

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