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 FeedsSmall block Chevy builders have another cylinder head option. Check out these CNC-ported SBC heads from Power Products.
More...
Chad Green is having one heck of a season. Green wants to use a victory at Bristol to launch him deep into the Funny Car title hunt.
More...
John Force Racing has one heck of a race shop. We take you along on a special VIP tour of the team's massive Indiana facility.
More...
NDRC Pro Mod racer Adam Tassone walked away from a violent crash that saw his Camaro catch air and take flight.
More...
Mustang Week 2026 introduces Street Kings, a new drag racing class for street-driven Ford vehicles. Learn more about the class right here.
Recent Technical Articles
Leah Pruett And Matt Hagan Face Massive Opportunity At NHRA Thunder Valley Nationals
Leah Pruett could leave Thunder Valley with a lot of hardware. Matt Hagan is looking for a win at one of his favorite tracks on the tour.
NewsSource Today, 07:10 AM