Drivetrain Manual Transmissions and Components

OS Giken

OS Giken Mazda RX7 FD3S 13BT 5 Speed Close Ratio Gear Kit w/ Input Shaft

$2,910.00

SKU: O002 MZ121-GC

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $100
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Description

Part #: MZ121-GC

MIA's Description

Your drivetrain is all the components responsible for transferring power from your engine and delivering it to the wheels. Drivetrain components are vital to your vehicles operation. Starting in the early 1960s, Masaharu Okazaki set out on a mission to build high-performance Japanese race engines to compete with the championship-winning European offerings of the time. Armed only with a pure passion for motorsports and an innate ability to absorb information, he basically took things apart in his garage, figured out how they work, and designed improvements to increase performance. A self-educated man, he originally began working on motorcycles and eventually moved on to parts development for 4-wheel automobiles. Mr. Okazaki founded his company, OS Giken, in the early 1970s with strength, durability, and the pursuit of high performance in mind; these goals for parts development remain true today and OS Giken has established itself in the upper-echelon for designing and manufacturing high quality, high performance, and supremely durable parts. From Mr. Okazaki's humble beginnings tinkering with motorcycle parts at home, OS Giken has evolved and grown over the years, building and cementing a reputation as one of the best racing drivetrain parts manufacturers in the world. Officially founded in 1973, the company headquarters and factory are located in Okayama, Japan. All OS Giken parts are 100% manufactured and assembled in Japan, under very strict quality-control guidelines. Production and design capabilities for engine and drivetrain components are OS Giken's specialty, but the company has the ability to design and build just about anything mechanical. As the design, construction, and usage of the automobile evolves, OS Giken looks forward to the challenges presented to find room for improvement! OS Giken MZ121-GC

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandOS Giken
Part NumberO002 MZ121-GC

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy