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 FeedsAustin Prock failed to qualify in his debut with Bob Tasca's team at the NHRA Gatornationals after a shocking offseason move.
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ATI Performance built these SFI Flexplate Kits to handle massive horsepower. Protect your custom GM driveline from catastrophic failure.
There's always people who are going to scream the sky is falling. Contrary to the internet tells you, drag racing is doing fine.
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Gary Pritchett takes over as the 2026 Top Fuel driver for Foley Racing. Owner Doug Foley plans to expand their NHRA and IHRA presence.
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The Flexjet NHRA Factory Stock Showdown expands its 2026 calendar. This nine-race season guarantees intense V8 muscle car drag racing.
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Recent Technical Articles
Inside Racing Fasteners: Why Strength, Stretch, And Threads Matter
Fasteners play a critical role in high-performance engines. Here's a look at what makes a high quality fastener work.
NewsSource Yesterday, 11:31 PMMore...