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 FeedsJason Collins continues to be the hottest driver in NHRA Pro Mod. Collins survived a wild week at Bristol and brought home the win.
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The NHRA Thunder Valley Nationals was an action packed affair. We've got a full recap of all the race day highlights right here.
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Friday was full of big moments at Bristol. Leah Pruett and Jack Beckman scored wins from the rain-delayed New England Nationals.
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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.
Small block Chevy builders have another cylinder head option. Check out these CNC-ported SBC heads from Power Products.
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