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 fields were set Sunday for the U.S. Nationals. Jack Beckman was able to win the Funny Car All Star Callout.
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#2Fast2Tasty Challenge results from the 2026 NHRA U.S. Nationals. Langdon, Capps, Hartford and Herrera led Saturday qualifying.
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Qualifying kicked off Friday at the U.S. Nationals. Langdon, Beckman, Stanfield, and Smith took the provisional No. 1 qualifying spots.
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Spencer Hyde is in the 2026 PlayNHRA All-Star Funny Car Callout at the U.S. Nationals. He?ll race a star-studded field for an $80,000 prize.
The Factory Stock Showdown field at Indy is stacked with great racers. Jonathan Allegrucci is trying to seal the points title at the Big Go.
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Jason Collins? U.S. Nationals Pro Mod Qualifying Runs Disallowed
Pro Mod racer Jason Collins faced issues at the U.S. Nationals. His qualifying runs were disallowed after a blower issue was discovered.
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