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GM HEI upgrade....Is it plug and play or wiring involved?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by bigburban383, Mar 21, 2004.

  1. bigburban383

    bigburban383 1/2 ton status

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    Has anybody upgraded their truck to HEI? I have a 90' TBI burban with a regular cap and separate coil. I know there are wires/connectors going in both the coil and the distributor so I am confused. Thanks /forums/images/graemlins/thumb.gif
     
  2. Thunder

    Thunder 3/4 ton status

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    I dont under stand what it is you want to do.
    Are you trying to upgrade the TBI ign in the 90?
    If so there is not much you can do. You already have a very good system. The Stock TBI system is better than the old style HEI. HEI would not be an upgrade.You cant use HEI(Coil in Cap) in a TBI truck it wont work with the computer.
    All you really need to do is get a MSD blasterII or Performance distributors Screamin Deamon coil. Both are plug and play.
    I also like the modules from:performancedistributors.com
    They give better low end throttle responce than the stock module
     
  3. Hossbaby50

    Hossbaby50 3/4 ton status

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    You have HEI. You don't have the more common of the HEI's which is the Big cap HEI but you have the Fuel Injection version with the small cap HEI.

    If you want to upgrade the ignition toss on a set of good plug wires (MSD, Taylor, etc) and a high performance coil (MSD, etc.) That should up your spark a decent amount for not to much money.

    Actually the small cap HEI is easier to upgrade then the big cap. Keep what you got and leave it stock (it should do ok stock) or hop it up a little if you want some more spark. I am running MSD wires on my small cap and might go with the MSD coil soon.
     
  4. bigburban383

    bigburban383 1/2 ton status

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    Okay, I was under the assumption that HEI was better than what I had. I just have to splice the two wires going in my stock coil to go into like an MSD coil?
     
  5. SUBFAN

    SUBFAN 1/2 ton status

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    I think it would be 'plug and play'
     
  6. Thunder

    Thunder 3/4 ton status

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    As I said in above post its plug and play. MSD makes a coil that will plug right in. All you have to do is drill out 2 rivits and bolt it in the housing.
    DUIs(performance dist) are pulg and play just bolt them on.
    [​IMG]
     
  7. Hossbaby50

    Hossbaby50 3/4 ton status

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    You get the late model GM HEI dual connector coil from MSD and it is a direct replacement I believe. No mods, just R&R and plug the 2 connectors in.

    Good plug wires should come before a coil though. If your plug wires won't transmit the extra power of the new coil to the spark plugs then you gain nothing. So you need to work from the spark plugs back on power transmission in an ignition system.

    plug wire then coil

    Harley
     
  8. bigburban383

    bigburban383 1/2 ton status

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    [ QUOTE ]
    As I said in above post its plug and play. MSD makes a coil that will plug right in. All you have to do is drill out 2 rivits and bolt it in the housing.
    DUIs(performance dist) are pulg and play just bolt them on.
    [​IMG]

    [/ QUOTE ]

    /forums/images/graemlins/doah.gif
     
  9. bablazer73

    bablazer73 1/2 ton status

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    Stay with what you have. It's an H.E.I. with the coil seperated. And if your in the mood to make things even slightly better, Move the coil AWAY from the engine heat. 1 of the problems running an std. H.E.I. is the coil is in the distributer. They make kits to get the coil AWAY from engine heat. I know it seems trivial, The power loss might not even be noticed, BUT, why take a chance. And you can move it FOR FREE!!
     

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