{"product_id":"yukon-gear-63-65-muncie-m20-m21-m-t-w-synchros-bearing-kit","title":"Yukon ZMBK117WS Muncie M20 7\/8in 4-Spd Bearing Kit w\/Synchros for 1963-1965 GM","description":"\u003ch4\u003eVehicle Fitment\u003c\/h4\u003e\u003cul\u003e \u003cli\u003e1963-1965 GM vehicles equipped with a Muncie M20 4-speed manual transmission (cast aluminum case, 7-bolt side cover, 7\/8\" countershaft pin, 80mm OD input bearing)\u003c\/li\u003e \u003cli\u003eCommon applications include Chevrolet Bel Air, Biscayne, and Impala (283\/327\/409ci); Chevelle, El Camino, and Malibu (283ci); Corvette (327ci); Nova\/Chevy II (283\/327ci); Oldsmobile Cutlass and 4-4-2 (330ci); and Pontiac Catalina, GTO, Le Mans, Tempest, and Grand Prix (326\/389ci) models built with this transmission\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eFitment Notes\u003c\/h4\u003e\u003cul\u003e \u003cli\u003eConfirm your transmission has an 80mm OD input bearing - a similar-looking 1963-1964 M20 kit exists for a 72mm OD input bearing and is not interchangeable with this kit\u003c\/li\u003e \u003cli\u003eFits the 7\/8\" countershaft pin M20 case only; the later 1966-1974 Muncie M20\/M21\/M22 uses a 1\" countershaft pin and requires a different kit\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eFeatures\u003c\/h4\u003e\u003cul\u003e \u003cli\u003eComplete bearing and synchro rebuild kit for the early Muncie M20 4-speed transmission\u003c\/li\u003e \u003cli\u003eIncludes all new bearings required for a full rebuild\u003c\/li\u003e \u003cli\u003eIncludes new synchronizer rings for smoother, more precise shifting\u003c\/li\u003e \u003cli\u003eIncludes new seals and gaskets to restore proper sealing after rebuild\u003c\/li\u003e \u003cli\u003eIncludes a small parts kit with snap rings, thrust washers, and needle bearings\u003c\/li\u003e \u003cli\u003eManufactured by USA Standard Gear for Yukon Gear \u0026amp; Axle\u003c\/li\u003e \u003cli\u003ePurpose-built for the 7\/8\" countershaft pin, 80mm OD input bearing M20 case\u003c\/li\u003e \u003cli\u003eConsolidates all major wear components into a single kit for a complete rebuild in one order\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eSpecifications\u003c\/h4\u003e\u003cul\u003e \u003cli\u003eTransmission: Muncie M20 4-speed manual\u003c\/li\u003e \u003cli\u003eApplication years: 1963-1965\u003c\/li\u003e \u003cli\u003eCase type: Cast aluminum, 7-bolt side cover\u003c\/li\u003e \u003cli\u003eCountershaft: 7\/8\" pin\u003c\/li\u003e \u003cli\u003eInput bearing: 80mm outside diameter\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eIncluded Components\u003c\/h4\u003e\u003cul\u003e \u003cli\u003e1x Complete bearing set\u003c\/li\u003e \u003cli\u003e1x Synchronizer ring set\u003c\/li\u003e \u003cli\u003e1x Seal and gasket set\u003c\/li\u003e \u003cli\u003e1x Small parts kit (snap rings, thrust washers, needle bearings)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eProduct Description\u003c\/h4\u003e\u003cp\u003eThe Yukon ZMBK117WS is a complete bearing and synchro rebuild kit for the early Muncie M20 4-speed manual transmission used in a range of GM performance cars from 1963 to 1965. It bundles all the wear-prone internal components - bearings, synchro rings, seals, gaskets, and small hardware - into a single kit, giving restorers everything needed to bring a tired or noisy early Muncie back to proper working order without hunting down parts individually.\u003c\/p\u003e\u003cp\u003eThis kit is built specifically for the earliest Muncie case design: cast aluminum construction with a 7-bolt side cover, 7\/8\" countershaft pin, and 80mm OD input bearing. This early M20 is easy to confuse with later-looking kits that use a different bearing size or a larger 1\" countershaft pin, so verifying your transmission's exact specs before ordering is important to avoid a mismatched kit.\u003c\/p\u003e\u003cp\u003eIt's a solid fit for owners restoring an early Bel Air, Impala, Chevelle, Corvette, Nova, GTO, or similar GM muscle car with a numbers-matching or period-correct M20, as well as anyone rebuilding this transmission for a swap. Installation requires full disassembly of the transmission and is best handled by someone experienced with manual transmission rebuilds or a qualified transmission shop.\u003c\/p\u003e\u003cmeta name=\"description\" content=\"Revitalize your 1963-1965 GM Muncie M20 transmission with this complete bearing and synchro kit. Perfect for classic restorations!\"\u003e\u003cmeta name=\"keywords\" content=\"Yukon Muncie M20 bearing kit, 1963-1965 GM transmission rebuild kit, manual transmission parts, synchronizer ring set for M20, 4-speed manual transmission restoration, cast aluminum Muncie case components, automotive parts for Chevrolet muscle cars, early Muncie transmission rebuild essentials, complete bearing set for GM transmissions, Yukon Gear \u0026amp; Axle performance parts.\"\u003e","brand":"Yukon Gear \u0026 Axle","offers":[{"title":"Default Title","offer_id":53864411824447,"sku":"YUKZMBK117WS","price":157.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0832\/7308\/9343\/files\/77629fa04db987b84f208977c57bf814L.jpg?v=1782577439","url":"https:\/\/wcaperformance.com\/products\/yukon-gear-63-65-muncie-m20-m21-m-t-w-synchros-bearing-kit","provider":"WCA Performance","version":"1.0","type":"link"}