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Help on how 75 3/4 ton chokes cali got heat

Discussion in 'Tech Discussion' started by milsurpman, Jul 15, 2021.

  1. milsurpman

    milsurpman Junior Member

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    Truck Year:
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    My cali 75 3/4 ton 454 is missing heat line to choke anyone have pictures or parts source. Attempting to keep choke on mostly stock truck. I-want to keep oem choke without deacting. Nothing obvious on initial inspection of where it mounted. Thanks john
     
  2. Bextreme04

    Bextreme04 Full Access Member

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    75 would still be a thermal coiled spring bolted to the intake manifold with a rod connected to the choke lever, right? My 80 has the hot air choke, and I can post a pic of that routing... but you probably want to convert it to an electric one if at all possible. My 74 C20 had the coiled spring version.

    Pics of what is currently there would be helpful. The choke parts should all be on the passenger side of the intake manifold and carburetor.
     
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  3. milsurpman

    milsurpman Junior Member

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    What’s bad is parts list for Cali 75 454 shows hot air pn gm 343739 for california for line. It appears to be an oddball external And I have no idea how it was run obviously I can’t get that part number I’ve looked. It will probably become no choke on this vehicle.
    .
     
    Last edited: Jul 15, 2021
  4. milsurpman

    milsurpman Junior Member

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    what kit did you use to go electric and block vacuum in housing.I can shoot you a picture of the right side of the carb It has dual diaphragms for choke pull off and ops connected to the original electric components on rear I removed hose it was split.and obviously the hot air diaphragm assembly. Cali stuf. Air pump and pluming pulled in pick pump is locked.
     
    Last edited: Jul 15, 2021
  5. milsurpman

    milsurpman Junior Member

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    upload_2021-7-15_14-50-26.jpeg
     
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  6. milsurpman

    milsurpman Junior Member

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    Solenoid went to rear choke pull off it was bad hose I’m replacing it after carb rebuild.It is Leaking from all it seems good dichromate I will pull the number on the carburetor when I pull it off but it appears to be the original.
     
    Last edited: Jul 15, 2021
  7. Bextreme04

    Bextreme04 Full Access Member

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    I'll look for some pics when I get home. I bought a kit from quadrajetparts.com for the electric conversion. Theres no need to block off the vaccum into the choke valve body as it is a metered leak. You can just cap the outlet where the solid pipe would normally go into the body. On mine there is a solid pipe that loops from the choke body down into the port on the intake manifold. Then another one that looped up and connected to the nipple on the top/back of the carb. On yours, you can see that nipple has a cap on it. The rear pull-off had a hose going down to a nipple at the rear/base of the carb.

    It gets VERY hot and I had problems with it melting wiring harness to the alternator that got too close. The new motor I'm putting together will be using an older intake manifold that didn't have an EGR or hot air choke port on the manifold. If you want to keep the same manifold, I'd recommend just creating your own blockoff plate and use a stock gasket to seal it off. The electric conversion kit was less than $50... I don't remember exactly how much though. If the truck is an unknown age, I'd recommend you order a rebuild kit and the conversion kit together and take the carb off to do it all at the same time. Clean it out real good and rebuild the whole carb and convert it to electric at the same time.
     
  8. milsurpman

    milsurpman Junior Member

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    Thanks a lot that’s my plan! Off it goes.
     
  9. Craig 85

    Craig 85 Full Access Member

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  10. GMFORLIFE

    GMFORLIFE Full Access Member

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  11. GMFORLIFE

    GMFORLIFE Full Access Member

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  12. Raider L

    Raider L Full Access Member

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    Pardon me while I go outside and throw up.
     
  13. milsurpman

    milsurpman Junior Member

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    Thanks for the info guys!
     

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