Well I came up with the The number of turns head thread Test.
Basically there is a seat in the head for the wider portion of the plugs just above the threads to stop on. This seat, notch, ledge, whatever... read more

Mustang FeedsThe NHRA 4-Wide Nationals at zMAX Dragway bring high-stakes action. JFR drivers are ready to chase wins, momentum, and championship position.
Chad and Hunter Green are ready for the 4-Wide Nationals. Here's what the father and son duo have planned for zMax Dragway.
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Ron Capps and Maddie Gordon each have an opportunity to have a big weekend at zMax. Both drivers are hunting for a 4-wide win.
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The couple that races together stays together. Nick Cole-Mann and Sarah Jaeger have built two quick stick-shift GM trucks.
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Spencer Hyde is ready to have a big weekend at zMAx. He has a new sponsor on the side of his Head Racing Funny Car for the event.
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Recent Technical Articles
From Factory X to IHRA Bratz: Holbrook Family Converts S650 Mustang To Twin Turbos
Del Holbrook has made the move to IHRA Bratz racing and has more tricks up his sleeve. His Mustang has been converted to a twin-turbo setup.
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