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's first visit to Maryland International Raceway was epic. Here's who won at the first NHRA Potomac Nationals.
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The NHRA Mission Food Series kicked off qualifying Friday at the Potomac Nationals. Here's who sitting number one in each class.
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Eric Russell wanted to build something that wasn't a Mustang for his project car. Russell's 1985 Thunderbird is a supercharged beast.
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You never know what you'll need during a drag-and-drive. We take a look at what goes into building and stocking a drag-and-drive trailer.
Tony Stewart Racing is ready for the Potomac Nationals. Leah Pruett and Matt Hagan are looking for big performances at MDIR.
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Recent Technical Articles
Shakedown at M?Town Delivers Records, Side-By-Side Racing, and Big Wins at US 131 Mot
The Shakedown At M'Town put on a great show. Here's all the highlights from this Pro Mod and radial racing event.
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