Wanting Spark Plug and plug wire suggestions for a 51 308

What spark plugs and plug wires work best for a 51 308 with 12 volt conversion and a stock distributor?


  • Glowplug
    Glowplug Expert Adviser
    edited February 2023
    The following information is posted to my website and was provided by Christian Chandler

  • Ok, thanks for those numbers.  My concern was if different plugs and wires were needed due to the 12 volt conversion.
  • Plugs and wires do not care about 6v vs. 12v electrical systems.  Your coil has bumped the voltage up to over 10,000 volts to travel down the wires and  jump the gap in the spark plug.

    Plugs will vary for application based on how "hot" they are.  This is slightly off topic, but it is why a 262 might (or might not) use a slightly different plug than a 308.  I know from personal experience that the NGK B6L works beautifully in a 7.2:1 compression 262.

    Glowplug, I have never seen both the first and last name wrong  (usually the last name). "cellor" DNE "dler" and "topher" DNE "tian"

  • Glowplug
    Glowplug Expert Adviser
    Sorry for the sloppy attribution spelling  :|  should be Christopher J Chancellor
  • ski4life65
    ski4life65 Expert Adviser
    Champion stopped making the H-11 many years ago. I do have a pretty big supply of NOS H-11 plugs if anyone is interested.
  • If the engine is operated under consistently high temperatures, a colder plug
    should be used. If the engine is operated under consistently low engine
    temperatures, a hotter plug should be used - this helps prevent carbon fouling.  Hotter plugs could cause pre-ignition with higher compression.  Engine configuration and driving conditions determine the spark plug selection.

  • My intention here was to canvas the crowd and see what seems to work and what to avoid based on individual experience. So, What's in your 308?
  • I'm using H-10's
  • RichardD
    RichardD Member
    edited February 2023
  • Auto-Lite 216 plugs from NAPA have been working fine for me in a 52 308 since a tune up a couple of years ago.  They're also very economical.
  • I like reading the provided info on spark plugs. I have a built GM HEI going into my 308 engine. Of I remember correctly, the plugs that were on my engiine. What  talking about is not the plug itself. It is the compression gasket at the bottom of the plus
  • super-six
    super-six Expert Adviser
    Autolite 437. Anything colder would foul.
  • What does Autolite 437 cross-reference to in Champion?  H11, H10, Other? 
  • For wires, I buy a set for 68 Camaro small block V8. Use the six shortest plug wires and the coil wire.
  • super-six
    super-six Expert Adviser
    Bitburger: "What does Autolite 437 cross-reference to in Champion?  H11, H10, Other?"

    It's been a few years but I believe it was H-12.
  • Auto-lite 437 cross-references to NGK B-4L which cross-references to Champion H11.  This is per the NGK cross-reference I dug up.
  • Ok, Thanks