Coil choices for my truck?

Slant 6 Engines

  1. halfafish

    halfafish Damn those rabbits, and their holes! FABO Gold Member

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    Despite the one-step-forward two-steps-back progress I'm making, the new slant for the truck is almost done. I was going to replace the coil with an upgrade unit, but there were many choices and no clarity as to which one would be correct. Or maybe I'm over thinking this...

    I'm looking for one to fit the stock location, about 40K volts or so. The engine is moderately built for a slant with a Super Six dizzy and HEI conversion already done. The confusing part is resistance of the coil, and how that is supposed to affect things. A bunch of internet digging hasn't helped clear this up any.

    What say the experts?
     
  2. RustyRatRod

    RustyRatRod I was born on a Monday. Not last Monday. FABO Gold Member

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  3. mopowers

    mopowers Well-Known Member

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    • Agree Agree x 1
    • 67Dart273

      67Dart273 FABO Gold Member FABO Gold Member

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      If you are actually running GM style HEI and not some chinese import "ready to run" (I don't know about them) The GM HEI modules seem to be very un-particular about coils. Several E coils are run by many, as an experiment I just ran the stock old beat up Mopar coil on my 67. It produces noticeably stronger spark, and doesn't seem to hurt either the module or the coil
       
    • Kendog 170

      Kendog 170 Let the boy go !

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      I'm not an expert on this but I believe you can run the MSD Blaster 2 coil with HEI and you don't need a Ballast resistor. Please anyone chime in if I'm wrong I would hate to give you Bogus info.
       
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      • Bewy

        Bewy Well-Known Member

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        If the module used is the GM module, then best to use an E core coil. These are more efficient than a canister coil & more energy gets to the spark plug tip. As mentioned above the MSD Blaster SS [ #8207 ] is a great coil that packs a powerful 300mA spark. No ballast resistor needed & adding a BR would degrade spark output.
         
      • halfafish

        halfafish Damn those rabbits, and their holes! FABO Gold Member

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        I grabbed a MSD Blaster 2 from the local speed shop. Thanks for the input, folks.
         
      • BillGrissom

        BillGrissom Well-Known Member

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        An e-core coil is best. Some choices are:
        1985-95 GM "external coil". Best if using the GM 8-pin HEI since a GM cable connects the two.
        ~1980-2000 Mopar Magnum engine coil (mounts at front top of the engine). Snip the lead and connector since you will be soldering.
        Chinese e-core from same ebay sellers of "ready to run" Ningbo distributors (Steve White Perf., ... ~$20). Has screw terminals.
        Ford TFI coil. Snip their special connectors.

        Main one to avoid is a factory "ballasted coil" which I think were late 1970's or early 1980's. They look like the 1960's coils, but I think have stamped "for electronic ignition". I have one, but haven't fooled with it. I think the primary (12 V) side has more resistance, replacing the need for a firewall ballast resistor. But, the resistance is still so low it is hard to distinguish with a multimeter. I guess you could tell if you ran it without a firewall ballast and it didn't get so hot it melted the paint like happens with a 1960's coil. That means they can't bypass the ballast when starting, but maybe they found w/ hotter e-ignition that wasn't needed. Perusing wiring diagrams of those years might tell, and an expert like SSD might say I'm FOS, and might be true since mostly guessing.
         
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