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  1. #1

    Default Any GM build sheet gurus?

    Not sure if this is the right place to post.

    Early 70s GM build sheet lists a Z49 option as Canada Base,there seems to be limited information out there as to exactly what this consists of.

    Anybody know?
    Last edited by Richard; October-09-19 at 11:48 AM.

  2. #2


    Google it. It refers to equipment installed on vehicles intended for the Canadian market.

  3. #3


    ^ yes I did before posting,I am looking for a more specific definition of what exactly the equipment was,or the difference between the US and Canadian builds.

  4. #4


    I would assume one of the components of Z49 would be the speedometer/odometer would be in kilometers, the oil gauge in kilopascals, the temperature gauge in centigrade. The owners manual specs may be in Imperial measurements, I.E., fuel,oil and coolant capacity and tire pressure in kilopascals also. Owners manual printing in English and French.

    The majority of FMVSS and CMVSS standards overlap but not completely, some exceptions but some of it is how they are worded from memory.

    Oh, plus the certification label for FMVSS or CMVSS, has to match the country the vehicle is originally registered in.

    "We" as in dealership employees had limited information available to us as to vehicle content relative to RPO's. Another problem is that some times an RPO code was recycled, for one example LT-1 starting in 1970 designated a high horsepower small block in Corvettes and Camaros, in the 90's it designated the standard SBC V8 engine used in certain RWD cars from Corvettes, Camaros, Firebirds, Impala, Caprice, Roadmaster, Fleetwood Brougham. I remember one time needing the component breakdown for a unpublished RPO that was a U.S. and Canadian government specification, so restricted that the RPO was not referenced in any information that we in the dealerships or lower levels in GM Parts Division as it was known then had access to. I had to contact division engineering and went through several people before I got to someone who's first question was "How did you get that RPO?" I only got very sketchy information and a Area Code 202 number, a government agency to plead my case for details. I passed that on to my customer, a well known prototype build shop, don't know how more successful they were than I was. Today that same RPO is for an 18" Aluminum wheel for some GM line.

    For more specific information the Internet is probably the best source for this. You might try to contact GM but I'm not thinking you will get much satisfaction there especially if it is one the now shuttered divisions. The "new" GM has pretty much forgotten the past, anything that is the "old" GM has been forgotten.

    Last edited by shovelhead; October-12-19 at 08:54 PM.

  5. #5


    Thank you very much,you actually provided more then an Internet search turns up,which was what I was looking for.

    We are dealing with trying to document the ever hated 73-77 El Camino,The Canadian side was also interested in the difference.

    The Z28 site and pretty much every other GM site also has the same unanswered questions.So they were also no help.

    I spent 3 hours a day in 110 heat pulling out a 70 350 engine in the middle of a field that the casting numbers had pulled up as a 1970 Z28 only to measure the journals and find out it was a late 70s to 80s smog junk motor.

    So I am familiar with the recycling of the numbers game.

    I fell into my el Camino when it was listed as haveing a 429 Cadillac transplant motor in,I was offered a 1963 caddy convertible with no rust and no motor or transmission for $1500.

    So I bought the el Camino and it turns out the motor is actually a 1963/1964 only Cadillac 390.

    So obliviously there are many confused when it comes to figuring out the mindset of GM and the rational when it comes to RPO and casting numbers.

    So now I am stuck with a nice caddy and a el Camino that will rival my boat when it comes to dumping thousands of dollars into that I will never see again.

    Anyways,with your permission I would like to copy and paste your reply to share with our el Camino group as it would be bringing us that much closer to understanding.

    If not that’s okay.
    Last edited by Richard; October-14-19 at 09:38 PM.

  6. #6


    You are more than welcome to post this information. And who hates the 73-77 El Camino? Certainly not me. Hey,that doesn't happen to be a black 77 Classic with a Firethorn interior with a VIN ending in 485211?

    I've been a hot rodder and motorcyclist for a long time, hence my screen name, still have a shovel in the garage. Retired GM dealership parts professional of 47 years concurrent with the last 20 as a part time H-D parts man.

    One thing, we were taught a long time ago that Chevrolet casting numbers meant little in determining what an engine was. Especially some of the stuff I saw during the early 1970's. In one of the HP series of Chevrolet books one writer stated that every block of a certain casting number was a four bolt block. Not so, saw plenty of them in two bolt configuration.

    Pontiac was no stranger to this either. Seen 400/428 engines that were factory sealed, block was machined, drilled and tapped four bolt mains but with two bolt mains, factory.

    Block stampings with engine codes are confusing also, those are only a small part of identifying what you have. Partial VIN's, block stampings along with block casting dates all help tell the tale. Throw in service replacement engines with no numbers stamped on them,good luck.

    Back to the El Camino of 73-77, I loved mine. Special ordered it with a 305 automatic transmission (only way I could have gotten a stick was if I had ordered it with a 250 6 cylinder then only a three on the tree) and F41 sport suspension. By the time it was two years old I had added factory cruise control, changed to a 350, dual exhaust with headers (quiet mufflers also, no racket for me) added a tilt steering column, a tonneau cover and the final piece, Corvette YJ8 Aluminum wheels. I preferred the 77 to the new downsized 78's. That 77 handled well, it was solid.

    I kick myself, my cousin's ex-husband bought a neighbor's 76 in the early 90's. He never did much with it, tore it down to rebuild it and never finished it. They divorced, I was offered it but I didn't need two projects at once, I was in the middle of my 67 Pontiac build at the time. If you need any more information PM me through here, I'll give you more direct contact information and I can give you what information that I can.

  7. #7


    By the way, if you did get lucky enough to find my El Camino and you think that the speedometer looks strange, you are right. Police package speedometer, if memory is correct as I sold it in 1983 but it was calibrated in two mile per hour increments up to 120 but they did not say "Certified" like many police options did. Another product of my "can't leave it stock" mindset.

  8. #8


    Richard, if the El Camino is in decent shape there are some ways to revive it without breaking the bank. As you know SBC's are starting to become "unicorns" and junkyard finds are fewer and farther.

    GM markets a new 350cid/290hp engine P/N 12499529, you would need an intake manifold, carburetor,distributor, water pump and exhaust as add ons. Warranty by GM for two years or 50k if memory is correct (I've been out of the business for almost two and a half years now). They did offer some with more content like an intake and air cleaner but all my books are at least two years old so some offerings could be changed. Price shop those, you will find a lot of bargains out there at times. But FYI if anyone offers you a P/N 10067353 and says "It's almost as good", RUN AWAY quickly. Those were a low horsepower engine that was not offered as a Performance Part, those were designed as a replacement engine for everyday 1985 and earlier vehicles and were and are pretty anemic. All in the camshaft grind.

    The TH350 transmission would be a good easy bolt in, better would be to use the 700R4 but that could be a whole new can of worms, PM me for details.

  9. #9


    The GM Media Archives in Sterling Heights might have some information, but most of what they offer the general public (aside from providing dealer invoices from VINs) is prepackaged stuff, I doubt they would look up a small obscure thing.

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