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 PDRA hit Bristol Dragway for the Thunder Valley Throwdown. Here's a recap that covers all the action from Thunder Valley.
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The Southeast Gassers Association put on a show at Rockingham Dragway. See who brought home the wins at this huge double header.
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Tom Hoffman turns heads in his Mustang, and he is going to get even more looks as he hired Mike Szalay to give it a slick new paint job.
Elite Motorsports is making a big chassis change before the Countdown. The team will be moving to Jerry Haas Race Cars moving forward.
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Drag Illustrated's World Series Of Pro Mod is moving again. The event will relocate from Bradenton Motorsports Park to the Texas Motorplex.
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A New Home: Summit Motorsports Park Steps Up To Support IHRA World Finals
Summit Motorsports Park is ready to host the IHRA World Finals. Bracket racers will now have a place to race thanks to Bill Bader.
NewsSource Yesterday, 10:50 AMMore...