Utilizing a one-piece drill tap and solid steel inserts, this repair kit restores stripped 14 mm spark plug threads in aluminum cylinder heads. The set includes both long and short tap holders, an insert installer, and a swedger to seat the new threads in the original location. To accommodate different head thicknesses, the kit provides four insert lengths: 5/16" (7.9 mm), 7/16" (11.1 mm), 11/16" (17.5 mm), and 1" (2.5 cm).

Utilizing a one-piece drill tap and solid steel inserts, this repair kit restores stripped 14 mm spark plug threads in aluminum cylinder heads. The set includes both long and short tap holders, an insert installer, and a swedger to seat the new threads in the original location. To accommodate different head thicknesses, the kit provides four insert lengths: 5/16" (7.9 mm), 7/16" (11.1 mm), 11/16" (17.5 mm), and 1" (2.5 cm).