The Samsonas Motorsport E36 M3 Dogbox Gearkit is designed to fit into the original E36 5-Speed ZF S5D Housing. This gearkit features a new surface and profile big teeth, as well as a clutch shaft made from special driveshaft steel.  With straight cut forged steel gears, racers will notice minimum rolling resistance. Each Samsonas gearbox features super finished, shot-peened gears and internals for optimal quality, and all selectors, shifting fingers, protections, forks, and rods are made from billet steel for maximum reliability.  These gearboxes are suitable for: Rally Endurance Racing Time Attack Rallycross Circuit Hill Climb 4-Speed Ratios I     2,615 II     1,938 III     1,563 IV     1,316 5-Speed Ratios I     2,400     2,067    2,643 II     1,789     1,600    1,850 III     1,429     1,300     1,300 IV     1,174     1,110     1,110 V     1,000     1,000     1,000