70 GS original motor

Discussion in 'Wet behind the ears??' started by Dean Price, Nov 2, 2019.

  1. Dean Price

    Dean Price Active Member

    Looking at a 70 skylark gs 455! Is the vin stamped on the engine? How do I know if it came with the car?
     
    Stage 2 iron likes this.
  2. Stage 2 iron

    Stage 2 iron 480 IRON HEAD STAGE 2

    70 GS 455 the Vin number will be stamped on the deck below the number one and number three spark plugs. The engine code will be stamped by the dipstick on the deck sometimes the head gasket covers it or part of it.
     
  3. Dean Price

    Dean Price Active Member

  4. Philip66

    Philip66 Well-Known Member

    The stampings can be very hard to see, especially on a 50 year old car. Paint and grease will cover them up and any prior engine work can wipe them away completely if the block was decked.
    As Stage 2 Iron said you need to look between the two rear spark plugs on the drivers side. It helps to remove the plug wires. Then you want to gently scrape away the grease build up with a putty knife type of tool. I say gently because if you start gouging away with a screwdriver you can make it hard to read the numbers.

    After scraping the grease I use a tool wipe or a cloth soaked with a cleaner or degreaser or starting fluid, brake cleaner, lacquer thinner, etc.
    Then you can usually hold a cell phone camera close enough to take a bunch of pics to determine where you might need to clean more.

    These pics are from my own 70 GS455 so this is exactly what you're looking for.
    Look at the second and third pics and you can see how light the stampings are in the front if the block, and this is on a low mile car.

    The last 8 digits of the vin will also be stamped on the drivers side of the transmission just above the pan mounting surface. Much easier to see the Trans numbers than the engine numbers, easy to see if it has it's born with Trans.

    image.jpg image.jpg image.jpg image.jpg image.jpg image.jpg
     
  5. Dean Price

    Dean Price Active Member

    Really helpful info!
     
    Gregory Matarrese likes this.
  6. Philip66

    Philip66 Well-Known Member

    Glad to help!
    Just let us know if you have any more questions.
     
    Gregory Matarrese likes this.
  7. Dean Price

    Dean Price Active Member

    If a engine has been decked can you still tell if the motor is original to the car?
     
  8. flynbuick

    flynbuick Guest

    Try gun numbers raising fluid.
     
    Dano likes this.
  9. Philip66

    Philip66 Well-Known Member

    You CAN still check if it's the original engine to the car if it's been decked.

    The really light stampings shown above in my pics are from the front of the block, just above the timing cover. This area would never be machined over. Decking can obliterate the engine code between the spark plugs but not the front of the block.

    The last 8 are stamped in different places depending on the year, but you should be fine with a 1970. You'll probably have to remove the alternator/air conditioner bracket to have access to the front of the block.

    Good Luck!!
     
    Gregory Matarrese likes this.
  10. Awesome thread. I too am looking at a 70 GS 455 tomorrow and was wondering about vin on block and trans. Very helpful!
     
  11. Brian Albrecht

    Brian Albrecht Classic Reflections

    Welcome! What'd you find out? Pictures??
     
    Gregory Matarrese likes this.
  12. BrunoD

    BrunoD Looking for Fast Eddie

    Most of the times people forget that a BBB gas pedal is different then the SBB,some people do change that,but the steering shaft also is different on the BBB.Where it goes into the steering box,its held there by a bolt and on the SBB that part is welded on.Bruno.
     
    2dtrak likes this.
  13. The first question I have is whether or not the frame of the convertible should have all of these holes in it?
    CA76E712-98E5-40F2-8BE4-159BDA9E813F.jpeg



    The next question I have is the Vin number for the car appears to be stamped on the deck between the number one and three spark plugs. I thought the vin was on the front of the motor behind the power steering pump? And I thought that the code for the engine should be between the number five and seven spark plug on that side which should be SR? However what’s there appears to be an 120? Is this correct?

    2C1F7C44-29B2-483E-861E-24EADDE20EFC.jpeg 4D850C5E-64B3-4E88-A2B0-9BE59758E571.jpeg
     
  14. CA3A108E-58F8-4CD5-A480-CA62F7435B70.jpeg EF4BD182-7CE0-4EFE-9820-C569BE00B545.jpeg Here’s another issue. Besides the fact that there appears to be fairly amateur floor pan replacement, and some plastic on the quarters in front of and behind the rear wheels, it appears as though there is rot in the Cowl. You can see right through the driver side to the right of the brake booster and it would also appear as though there was some work done behind the windshield wiper motor. How big of an issue is this to correct properly?
     
    Last edited: Jan 29, 2020
  15. 773363D3-D483-4F6D-A246-E5B41616DC32.jpeg C2191C9A-5BAB-4104-ADED-BA0195B4352C.jpeg It would appear that the transmission is not original to the car. Can anyone tell from the vin and or tag what it originally came in?
     
  16. FFBEDD60-4F22-4CE4-90A7-15E91292213D.jpeg 6735B179-D8AA-48D7-9B5E-45EA6164D985.jpeg Here’s another question. This does not appear to be the original carburetor but can anyone decode it as well? Also the distributor does appear to be original and still have points in it. Can anyone confirm?
     
  17. Brian Albrecht

    Brian Albrecht Classic Reflections

    TH 400 usually BA, and yeah, that's not a match assuming block is correct

    My guess is the 2 letter engine code (i.e. SR) is just above the picture you took showing I20, possibly partly covered by the head

    Someone else needs to chime in on the engine VIN stamp (yes, that is where you frequently find it), but it looks a little irregular to me...

    Frame holes are normal

    Distributor and Carburetor are 1970 455"

    Cowl rust is a known issue
     
    Last edited: Jan 29, 2020
  18. Brian Albrecht

    Brian Albrecht Classic Reflections

    Did you take a picture of the cowl trim tag?
     
  19. flynbuick

    flynbuick Guest

    Caddy trans —maybe an 80 model.
     
  20. Stage 2 iron

    Stage 2 iron 480 IRON HEAD STAGE 2

    I'm not seeing the rust issue on the cowl I see two drilled holes that should be there. Looks like there's some paint flaking off above the brake booster if you're saying that's a rust hole you need to walk away unless you're a welding expert. I can guarantee that both lower corners of the cowl ate rotted out.
     

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