{"product_id":"usa-standard-ring-pinion-gear-set-for-gm-8-5in-in-a-3-73-ratio","title":"Yukon ZG GM8.5-373 GM 8.5in\/8.6in 10-Bolt Ring Pinion 3.73 for 1970-1998 GM","description":"\u003ch4\u003eVehicle Fitment\u003c\/h4\u003e\u003cul\u003e \u003cli\u003e1970-1998 GM 8.5\"\/8.6\" 10-bolt rear differential, used broadly across:\u003c\/li\u003e \u003cli\u003eChevrolet Camaro (1970-1981), Nova, Chevelle\/Malibu, Impala, Caprice, Monte Carlo, El Camino\u003c\/li\u003e \u003cli\u003eChevrolet\/GMC C10\/C1500 and K10\/K1500 pickups\u003c\/li\u003e \u003cli\u003eChevrolet\/GMC Suburban, Blazer\/K5 Blazer, and S10 Blazer\/Pickup\u003c\/li\u003e \u003cli\u003eChevrolet\/GMC G-series and Express\/Savana vans\u003c\/li\u003e \u003cli\u003ePontiac Firebird\/Trans Am and select Buick\/Oldsmobile full-size RWD models\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eFitment Notes\u003c\/h4\u003e\u003cul\u003e \u003cli\u003eCovers both the GM 8.5\" (1970-1998) and the physically similar 8.6\" design; confirm your ring gear diameter and pinion spline count match before ordering, since axle specs can vary by exact production year\u003c\/li\u003e \u003cli\u003e30-spline pinion only; some GM 8.5\" applications used a 28-spline pinion instead - confirm your spline count before ordering\u003c\/li\u003e \u003cli\u003eStandard rotation only\u003c\/li\u003e \u003cli\u003eA rare bolt-in-axle \"BOP-style\" variant of the 8.5\" was used in some 1971-1972 Buick, Oldsmobile, and Pontiac models - verify your differential type if your vehicle falls in that range\u003c\/li\u003e \u003cli\u003eThis is a ring \u0026amp; pinion gear set only - it does not include bearings, races, shims, or seals; pair it with a separate install or master overhaul kit for a complete gear swap\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eFeatures\u003c\/h4\u003e\u003cul\u003e \u003cli\u003eHigh-performance ring \u0026amp; pinion gear set for the GM 8.5\"\/8.6\" differential\u003c\/li\u003e \u003cli\u003e3.73 gear ratio\u003c\/li\u003e \u003cli\u003e30-spline pinion\u003c\/li\u003e \u003cli\u003e10 ring gear bolts\u003c\/li\u003e \u003cli\u003e8.500\" ring gear diameter\u003c\/li\u003e \u003cli\u003eManufactured by USA Standard Gear to exceed OEM specification\u003c\/li\u003e \u003cli\u003eDesigned for quiet, precise operation and straightforward setup\u003c\/li\u003e \u003cli\u003eBacked by a 1-year warranty against manufacturer defects\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eSpecifications\u003c\/h4\u003e\u003cul\u003e \u003cli\u003eDifferential: GM 8.5\"\/8.6\" 10-bolt\u003c\/li\u003e \u003cli\u003eRatio: 3.73\u003c\/li\u003e \u003cli\u003ePinion spline count: 30\u003c\/li\u003e \u003cli\u003eRing gear bolts: 10\u003c\/li\u003e \u003cli\u003eRing gear diameter: 8.500\"\u003c\/li\u003e \u003cli\u003eWarranty: 1 year against manufacturer defects\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eIncluded Components\u003c\/h4\u003e\u003cul\u003e \u003cli\u003e1x Ring gear\u003c\/li\u003e \u003cli\u003e1x Pinion gear\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eProduct Description\u003c\/h4\u003e\u003cp\u003eThe Yukon ZG GM8.5-373 is a high-performance ring \u0026amp; pinion gear set for the GM 8.5\"\/8.6\" 10-bolt rear differential, one of the most widely used rear axles in GM history - found under everything from Camaros and Chevelles to full-size trucks, Suburbans, and Blazers across nearly three decades of production. At a 3.73 ratio, this set is a common choice for restoring proper drivability after a tire size change, or for improving off-the-line torque on a performance build.\u003c\/p\u003e\u003cp\u003eBuilt with a 30-spline pinion, 10 ring gear bolts, and an 8.500\" ring gear diameter to match factory GM 8.5\"\/8.6\" specifications, this set is engineered for quiet operation and straightforward setup. Because this axle was used across so many different GM divisions and body styles over such a long run - with some early years using a 28-spline pinion instead of 30, and a rare bolt-in-axle variant appearing briefly in the early 1970s - confirming your exact axle spec before ordering is the key step.\u003c\/p\u003e\u003cp\u003eThis is a gear set only, not a full install kit - it doesn't include the carrier bearings, pinion bearings, shims, or seals needed to complete a gear swap. Pair it with an appropriate master overhaul or bearing install kit for your specific application. Installation requires differential disassembly and proper backlash and pinion depth setup, so it's best handled by an experienced DIY installer or a differential shop.\u003c\/p\u003e\u003cmeta name=\"description\" content='Upgrade your GM 8.5\"\/8.6\" differential with Yukon ZG GM8.5-373 3.73 gears for improved performance and drivability. Fitment for classic models!'\u003e\u003cmeta name=\"keywords\" content=\"Yukon ring and pinion, GM 8.5 10-bolt gear set, 3.73 gear ratio, high-performance differential, Chevrolet Camaro parts, 30-spline pinion gear, rear axle upgrades, differential setup kit, classic GM restoration parts\"\u003e","brand":"Yukon Gear \u0026 Axle","offers":[{"title":"Default Title","offer_id":53864411103551,"sku":"YUKZG GM8.5-373","price":228.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0832\/7308\/9343\/files\/2697e46dcf171e4aa4e6a397ba0141fa.jpg?v=1782577430","url":"https:\/\/wcaperformance.com\/products\/usa-standard-ring-pinion-gear-set-for-gm-8-5in-in-a-3-73-ratio","provider":"WCA Performance","version":"1.0","type":"link"}