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 continues to chase championships in Seattle. Here's a look at what the teams have planned for this weekend.
More...
The Gutierrez Brothers Racing Top Alcohol Dragster features a new M1 Concourse design as the Detroit-area venue opens a drag strip.
More...
IHRA?s Alleged Payment Issues Reportedly Extend Beyond Outlaw Nitro Series Cancellation. Here's what we know.
More...
Elite Motorsports has a head of steam heading to the Northwest Nationals. The Elite drivers want to continue their success in Seattle.
More...
Chad Green is having the best year of his nitro career. Green's goal is to use his momentum to pick up a Northwest Nationals win.
More...
Recent Technical Articles
Leah Pruett And Matt Hagan Target Seattle Success During NHRA West Coast Swing
Seattle is the next stop for Tony Stewart Racing. Leah Pruett And Matt Hagan are ready to finish the West Coast swing strong.
NewsSource Today, 08:30 AMMore...