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 FeedsJohn Force Racing is ready for a big weekend at the U.S. Nationals. All of the teams have their eyes on big wins and titles at the Big Go.
Alexis DeJoria is bringing back an old school John Force look at Indy. DeJoria's Funny Car will wear the "Night Stalker" livery at the Big Go.
NewsSource Today, 09:20 AM
RCM has some big opportunities at the U.S. Nationals. Bonus race wins and a regular season Funny Car points title are all on the line.
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Elite Motorsports is bringing some serious firepower to the U.S. Nationals. The team is ready to add another Pro Stock title to its resume.
Ron Capps is bringing a new look to Indy. His Funny car will be dressed in Carlyle green and be a part of the "tool wars" this weekend.
NewsSource Today, 08:20 AM
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TJ Zizzo Targets Breakthrough Top Fuel Win At The NHRA U.S. Nationals
TJ Zizzo returns to Top Fuel racing at the U.S. Nationals. Zizzo is chasing his first win and would love to make it a special one at Indy.
NewsSource Today, 10:50 AM