Goopy 13B Through-Studs

Goopy Performance through-studs for Mazda 13B with 12 point nuts and washers

For S6 and later engines or FD3S or 20B Cosmo Engines

These studs go through the entire engine with a nut on the front and on the rear

1/2" diameter with 1/2-20 thread pitch

Black oxide coated 4140 chromoly steel