Msd / Plug Gap

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Mar 3, 2005 | 01:56 PM

conway62

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From: Pinellas Park FL

Msd / Plug Gap

What is the best spark plug to run after installing a MSD 6AL ignition ?

Mar 3, 2005 | 03:07 PM

The Dude

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From: Calif.

Quote:

Originally Posted by conway62

What is the best spark plug to run after installing a MSD 6AL ignition ?

What you're running now should be fine if they're already the correct heat range, length, etc. You can now open up the gap an extra .050" or so.

Mar 3, 2005 | 03:20 PM

Gordonm

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From: Forked River NJ

I run the same plugs as before just went from .035 gap to .040 gap.

Mar 3, 2005 | 03:28 PM

conway62

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From: Pinellas Park FL

The gap is the real question. Sounds like 45 is about the norm.

Mar 3, 2005 | 03:46 PM

Fevre

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From: Living in the Hartland

HEI gap is .045, think you can go as high as .060 with the MSD, I am running the HEI gap with mine.

Mar 3, 2005 | 08:55 PM

stingr69

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From: Little Rock AR

If you have a high C/R you should run .035". The bigger gaps specified for factory HEI engines are used with low C/R, lean emissions type engines. You will not likely see any benefit from bigger gaps in most cases and the tighter gap is more reliable for higher C/R.

-Mark.

Mar 4, 2005 | 07:53 AM

Bobchad

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From: Norcross GA

I asked Lars the same question when I added the MSD box to my car. My recollection is he indicated .035 but in any event it was not wider than stock, contrary to the MSD recommendations.