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 controversy over Mack Racing vs Team White Rice spilled over on social media. Here's what we know about the situation.
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The NHRA Las Vegas Nationals always puts on a great show. Dragzine's Mark Riker grabbed these great images from The Strip.
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The NHRA has named Mitutoyo as its official precision measurement partner. The partnership will run through the 2029 season.
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Nicolas reset the LS elapsed time record at No Mercy. We take a look at the engine package and car that went 3.725 in the 1/8th mile.
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ProCharger's new monster F-4X-140-2 ProMod supercharger not only makes record-setting power, but already has a championship under its belt.
Recent Technical Articles
GM Files Patent For Camera-Based Drag Racing Launch Control
Cutting a good light is how you win races but that could be changing. GM has filed a patent for a camera-based launch control system.
NewsSource Yesterday, 01:44 PMMore...