1970 Z28 engine questions

Discussion in 'Original Drivetrain Topic' started by gpm6367, Jul 13, 2019 at 4:28 PM.

  1. gpm6367

    gpm6367 Veteran Member Gold Member

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    B4839F9B-D9FA-46A9-835E-1EEC8DB6CB38.jpeg 7CFF5EE1-CDB1-48A1-B3E1-722FA633AF69.jpeg D464A89C-BFD0-45A1-B270-8A5B0444766F.jpeg 45340372-722B-4FFE-A699-56B7AFD9131D.jpeg B2567BA1-D13B-4AA1-AA5B-481E05E0A6B4.jpeg 5E11329B-BA70-4D41-ABD0-BEC25BE48C77.jpeg BDCA8F69-500C-4D50-8D7D-8C1A224E3DA5.jpeg i am moving over from my acquisition thread to individual topics. I’m finally out of trunk and under hood to access what I’ve got here. I already know the block is a correct 70 Z28 casting but cast about 5 months after my car assembled so not original. Maybe warranty block, but not known at this time. The pad is clean.

    The carb is correct for 69 Z28/L78 and I will sell or trade that for rebuildable core. Carb looks wet which concerns me.

    Intake is clearly a Winters but off what? Where is casting number? I know the casting date is underneath and can’t be seen when installed. And that blue plug in front of intake on drivers side?

    The distributor unfortunately has electronics hidden under cap. I saw the date and was happy with Jan 30 1970 but then saw last 4 digits and 2002 is not the correct distributor. Anyone know what that came out of originally?

    I am looking forward to yanking the vintage air. What is that solenoid looking device on pass side of intake along top of valve cover? Part of AC system?

    Any help would be appreciated.
     
  2. Gary S

    Gary S Administrator Lifetime Gold Member

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  3. wnmech

    wnmech Veteran Member

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    My 71 winters intake manifold has the part number behind the carburetor
     

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  4. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    The solenoid device is part of the TCS transmission controlled spark system that restricted vacuum advance based on engine temperature and transmission gear. Basically the hose from the vacuum advance on the distributor connected to one port and the other port connected to a port at port he vase of the carb. The temperature sensor in the passenger head was part of the system and there was a wire to the 3-4 shift connection on the transmission. It was part of the emissions system.

    To find the intake casting number you have to pull the carb. It’s under the rear bowl.
     
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  5. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    If you are going to buy a distributor be careful. Many restamps out there and they are pretty good at it. Expect to pay 600+ for one that’s legit and even then be careful.
     
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  6. 70lt1z28

    70lt1z28 Veteran Member Gold Member

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    Hate to be the bearer of bad news but the intake is not original. Looks to be a 1969 intake or possibly the 3972116 service replacement intake. The factory installed intake didn’t have a metal freeze type plug in the front oil filler hole. It was cast over. They also didn’t have the drilled-tapped-plugged hole under the thermostat housing facing forward.

    You are also missing the very hard to find original throttle cable bracket for the Holley carb. It was special to the 70-72 Z28’s and LT-1 Corvettes.
     
    Last edited: Jul 13, 2019 at 8:39 PM
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  7. gpm6367

    gpm6367 Veteran Member Gold Member

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    I’m told the block was decked during s rebuild in the 80s but yet to verify.

    Ahh casting number behind the carb...I have to remove it to see it.

    Ok so I guess I’ll be picking up a distributor too. I want points anyway.
     
  8. gpm6367

    gpm6367 Veteran Member Gold Member

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    I saw that plug and I’ve seen original intakes and thought it was different. Got a feeling intake and carb off a 69 Z. Oh well, the parts list grows...
     
    Last edited: Jul 14, 2019 at 11:59 AM
  9. ronzz572

    ronzz572 Veteran Member Lifetime Gold Member

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    Eric you are also missing the correct throttle cable bracket 3980982 part number. Also you have a incorrect throtle return spring. Also the stamp rite fuel line support bracket is missing.
     
  10. gpm6367

    gpm6367 Veteran Member Gold Member

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    Wait...that’s for auto trans? The dorky solenoid isn’t on a 4 spd is it? Doesn’t appear attached to anything.
     

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