Mazda Rx7 Rotary 13B Oversize Black Oxide Hardened Engine Stud Kit

Speedmaster RX7 rotary engine stud kit fits all 13b engines. Replaces 16 of the engine thru bolts to chromeoly steel with black oxide coating. Includes factory washers. Our engine fasteners are made from aircraft quality 8740 high tensile strength chromoly steel and cold-forged to ensure molecular integrity. They are heat-treated prior to thread rolling and machining and are rated at a whopping 190,000 psi. All kits come complete with 12 point nuts and hardened parallel washers for an even load distribution and accurate torque readings.
The rear, center, and both rotor housings need to be drilled out with a 1/2" drill bit (not provided) to allow the oversize bolt to pass through.