Best Ring And Pinion Gears for GM and Ford Differentials

#1 · Best Overall

1. USA Standard GM8.5-373

• Weight: 17.67 lb
• Dimensions: 16 x 12 x 6 in

Best for: GM 8.5 3.73 replacement.

Why it ranks #1: It is specifically listed for a GM 8.5 differential with a 3.73 ratio and 12 ring gear bolts, plus a stated one-year defect warranty.

A 3.73 axle ratio and GM 8.5 differential application make this USA Standard Gear set a targeted choice for a compatible replacement or regear. Its 12 ring gear bolts identify a key installation specification, while the brand’s stated range of common and hard-to-find applications supports shoppers comparing axle-specific gear options.

The GM 8.5 application and 3.73 ratio give buyers two concrete selection points for narrowing a replacement or regear. The listed 12 ring gear bolts provide another relevant specification for planning the differential work. USA Standard describes the set as suitable for repair, rebuild, or regear projects, so it can serve more than one type of service job. It is a gear set, making this a focused choice rather than a bundled overhaul package.

Skip it if you need a Ford 8.8 application; the USA Standard Gear ZG F8.8-373 is listed for that differential.

Choose this set when your project calls for a 3.73 ratio in a GM 8.5 differential and you want gears for a repair or regear. Its application and bolt count make axle-specific compatibility essential.

Listed on Amazon as: USA Standard Gear (ZG GM8.5-373) Ring & Pinion Gear Set for GM 8.5 Differential

#2 · 10-Bolt GM Pick

2. Yukon GM8.5-373

• Weight: 17.7 lb

Best for: GM 8.5 or 8.6 3.73.

Why it ranks #2: This set specifies GM 8.5 and 8.6 differentials, a 3.73 ratio, 30-spline pinion, and 10 ring gear bolts.

Compatibility with both GM 8.5 and 8.6 differentials is the defining feature of this Yukon Gear & Axle set, giving buyers across those applications a 3.73 ratio option. The listing also identifies a 30-spline pinion and ten ring gear bolts, useful details when checking the intended differential setup.

The stated GM 8.5 and 8.6 coverage makes this set relevant to either listed differential size, while its 3.73 ratio identifies the gearing choice. Yukon specifies a 30-spline pinion and 10 ring gear bolts, details that help define the assembly for a planned installation. Its steel construction and Yukon’s stated quality-control process, including two in-house labs, provide additional context for buyers weighing material and manufacturing approach.

Skip it if you need a complete front-and-rear Jeep regear package; Yukon Gear & Axle YGK013 includes both axle gear sets and overhaul kits.

This suits a GM 8.5 or 8.6 owner choosing a 3.73 gear set and checking spline and bolt details before installation. It is not the bundled front-and-rear overhaul package for a Jeep.

Listed on Amazon as: Yukon Gear & Axle 3.73 ratio 30 spline pinion Ring and Pinion Set for GM 8.5" and 8.6" differentials

#3 · Complete Jeep Kit

3. Yukon YGK013 Jeep Kit

• Weight: 42.1 lb
• Dimensions: 12 x 14 x 20 in

Best for: Jeep JK front-and-rear regear.

Why it ranks #3: The 4.88-ratio package includes front and rear ring and pinion sets and overhaul kits for Dana 30 and Dana 44 axles.

Front and rear ring-and-pinion sets arrive with master overhaul kits in this Yukon package, enabling a coordinated 4.88 regear across a non-Rubicon Jeep JK. The matched package is specified for Dana 30 front and Dana 44 rear differentials, so buyers can plan both axles from one listed kit.

The 4.88 ratio applies to both included gear sets, while the Dana 30 front and Dana 44 rear specifications identify the axles the package serves. Front and rear master overhaul kits accompany the gears, bringing the listed rebuild components into the same purchase rather than requiring a separate installation-kit selection. Yukon describes the package as a simple one-part-number route to re-gearing a four-wheel-drive vehicle, but the specified Jeep configuration remains central to fit.

Skip it if you need a single GM 8.5 gear set; Yukon Gear & Axle YG GM8.5-373 lists that application and a 3.73 ratio.

Pick this for a non-Rubicon Jeep JK project requiring a 4.88 regear at both axles and overhaul parts in one package. Its Dana 30 and Dana 44 specifications define the required configuration.

Listed on Amazon as: Yukon Gear & Axle – Gear & Install Kit for Jeep JK non-Rubicon 4.88 Ratio – includes ring and pinion (4.88 ratio) – YGK013

#4 · 8620 Steel Pick

4. Motive Gear GM10-373A

• Weight: 16 lb
• Dimensions: 15.5 x 11 x 5.25 in

Best for: GM 8.5/8.625 3.73 gearing.

Why it ranks #4: This 3.73 set fits GM 8.5/8.625 10-bolt differentials and lists heat-treated 8620 steel construction.

A 3.73 ratio for GM 8.5 and 8.625 10-bolt differentials makes this Motive Gear set a specific option for those applications. Its 30-spline specification and 8620 steel construction add useful selection and material details for buyers planning a replacement or gearing change.

Motive Gear identifies the application as GM 8.5 or 8.625 10-bolt differentials, with a 3.73 ratio and 30-spline configuration. Those specifications help buyers narrow the set to a defined differential setup before beginning a gear change. The listed 8620 steel is heat-treated for wear resistance and durability, supporting use under heavy loads as described. The listing presents this as a gear set, not a package of bearings and other overhaul parts.

Skip it if you want an included master bearing and installation kit; the QP GM 8.5 3.73 package lists bearings, seals, shims, and hardware.

This is a focused choice for a GM 8.5 or 8.625 10-bolt project calling for 3.73 gearing and 30 splines. Plan separately for overhaul parts, since the listing covers the gear set.

Listed on Amazon as: Motive Gear GM10-373A Differential Ring & Pinion Set, 3.73 Ratio, 30-Spline

#5 · Install Parts Included

5. QP GM8.5-373 Kit

Best for: GM 8.5 kit-inclusive regear.

Why it ranks #5: It combines GM 8.5 10-bolt 3.73 gears with a master kit listing bearings, races, seal, shims, crush sleeve, and bolts.

A master bearing and installation kit is bundled with the 3.73 GM 8.5 10-bolt ring-and-pinion set, bringing gears and many installation components together. Listed kit contents include bearings, races, seals, shims, ring gear bolts, gasket, marking compound, brush, and thread-locking compound.

The 3.73 gears are specified for a GM 8.5 10-bolt application, while the included master kit supplies carrier and pinion bearings and races, a seal, nut, shims, crush sleeve, and ring gear bolts. The package also lists a gasket, marking compound, brush, and Lock-Tite, consolidating numerous installation items for the job. Its bearing kit fits stock carriers; buyers using aftermarket Eaton or Auburn Posi units should note the listing points to a different bearing option.

Skip it if you have an aftermarket Eaton or Auburn Posi unit; the listing directs those setups to a different bearing option.

Consider this package for a GM 8.5 10-bolt 3.73 installation on a stock carrier when bundling gears and setup parts is useful. Its stated carrier limitation matters for aftermarket Posi units.

Listed on Amazon as: CHEVY GM 8.5" 10-Bolt Ring and Pinion 3.73 Ratio Gears & Master Bearing/Installation Kit

#6

6. USA Standard Ford 8.8-373

• Weight: 16 lb
• Dimensions: 19 x 14 x 6 in

Best for: Ford 8.8 3.73 replacement.

Why it ranks #6: This is a Ford 8.8-specific 3.73 set with 10 ring gear bolts and an 8.80-inch ring gear diameter.

Ford 8.8 differential fitment paired with a 3.73 ratio defines this USA Standard Gear set, giving Ford owners a focused option for replacement gears or a ratio change. The listing specifies ten ring gear bolts and an 8.80-inch ring gear diameter, adding useful application details for installation planning.

The Ford 8.8 application and 3.73 axle ratio narrow the set to a particular regear or replacement task. USA Standard lists 10 ring gear bolts and an 8.80-inch ring gear diameter, details that help identify the configuration under consideration. The manufacturer describes its gears as suitable for replacement and ratio changes, while the product listing presents a gear set rather than a bearing or overhaul kit. That keeps the purchase focused on the specified gearing components.

Skip it if you need GM 8.5 or 8.6 fitment; WFLNHB GM8.5-373 is listed for those differential sizes at a 3.73 ratio.

This fits the decision for a Ford 8.8 owner selecting 3.73 replacement or regear components. Its listed bolt count and ring gear diameter offer concrete identifiers, but its specified application is not a universal axle fit.

Listed on Amazon as: USA Standard Gear (ZG F8.8-373) Ring & Pinion Gear Set for Ford 8.8 Differential

#7

7. Motive Gear F8.8-373A

• Weight: 11.84 lb
• Dimensions: 15.5 x 11 x 5.25 in

Best for: Ford 8.8 3.73 gearing.

Why it ranks #7: It targets Ford 8.8 10-bolt differentials at a 3.73 ratio and specifies heat-treated 8620 steel.

A 3.73 ratio in a Ford 8.8 10-bolt application is the defining combination in this Motive Gear set, giving Ford differential owners a clearly specified regear option. The listing adds 30-spline fitment and heat-treated 8620 steel, supporting an informed choice around configuration and material.

Motive Gear specifies the Ford 8.8 10-bolt differential, a 3.73 ratio, and 30 splines, making the intended configuration easy to identify. Its 8620 steel gears are heat-treated for wear resistance and longevity, with the product description citing heavy-load use. The listing also characterizes the set as an OE replacement with precision fit, which supports buyers planning a replacement rather than a bundled rebuild. It is a focused gear set, not an installation-kit package.

Skip it if you need 3.55 gearing for a Ford 8.8; Motive Gear F8.8-355A lists that ratio for the same differential family.

Choose this for a Ford 8.8 10-bolt project calling for 3.73 gearing and the listed 30-spline configuration. Its heat-treated steel is a stated material feature, while installation components are not bundled.

Listed on Amazon as: Motive Gear F8.8-373A Ring and Pinion 3.73 Ratio 30spl 10Bolt For Ford 8.8

#8

8. Motive Gear GM10-342A

• Weight: 17.7 lb
• Dimensions: 15.5 x 11 x 5.25 in

Best for: GM 8.5 3.42 ratio.

Why it ranks #8: Its 3.42 ratio and 8620 steel construction suit buyers specifically seeking gears for GM 8.5/8.625 10-bolt axles.

The 3.42 ratio distinguishes this Motive Gear set among the listed GM gear options, giving GM 8.5 and 8.625 10-bolt owners a defined gearing choice. It combines that application with a 30-spline specification and heat-treated 8620 steel for buyers considering a replacement or ratio change.

Motive Gear lists GM 8.5 and 8.625 10-bolt differentials, a 3.42 ratio, and 30 splines, which together narrow the intended setup. The 8620 steel construction is heat-treated for wear resistance and durability, with the description also citing heavy-load use. This is useful context when selecting gears for daily driving or performance needs, both named in the listing. As a ring-and-pinion set, it does not provide the separately listed overhaul components found in a master kit.

Skip it if you require a 3.73 GM 8.5 set; USA Standard Gear ZG GM8.5-373 lists that ratio and differential application.

Choose it for a GM 8.5 or 8.625 10-bolt project where 3.42 gearing and the stated 30-spline setup are appropriate. Keep the ratio requirement central when selecting this gear-only set.

Listed on Amazon as: Motive Gear GM10-342A Ring & Pinion 3.42 Ratio 30 Spline 10 Bolt for GM 8.5

#9

9. Motive Gear F8.8-355A

• Weight: 0.01 oz
• Dimensions: 15.5 x 11 x 5.25 in

Best for: Ford 8.8 3.55 ratio.

Why it ranks #9: This Ford 8.8 10-bolt set offers a 3.55 ratio and lists 8620 steel construction for buyers whose target ratio matches.

The 3.55 ratio sets this Motive Gear ring-and-pinion apart for Ford 8.8 10-bolt owners seeking that specific gearing. It is listed with a 30-spline configuration and heat-treated 8620 steel, joining application, ratio, and material details in one focused replacement set.

Motive Gear identifies this set for a Ford 8.8 10-bolt differential with a 3.55 ratio, so the gearing choice is clear for a planned replacement or change. The 30-spline specification provides another key configuration detail. Its 8620 steel construction is heat-treated for wear resistance and durability, and the listing cites use under heavy loads. The product is a ring-and-pinion set; buyers should plan separately for bearings or other overhaul parts if their job requires them.

Skip it if you need 3.73 gearing for a Ford 8.8; Motive Gear F8.8-373A lists that ratio and differential application.

This suits a Ford 8.8 owner whose project calls for 3.55 gearing and the specified 30-spline configuration. The heat-treated steel is a stated benefit, but this gear set does not bundle overhaul parts.

Listed on Amazon as: Motive Gear F8.8-355A Diff. Ring and Pinion 3.55 Ratio for Ford 8.8" 30-Spline 10 Bolt

#10

10. WFLNHB GM8.5-373

• Weight: 18.04 lb
• Dimensions: 13.39 x 11.02 x 5.51 in

Best for: GM 8.5/8.6 towing use.

Why it ranks #10: It lists a GM 8.5/8.6 fit, 3.73 ratio, and 30-spline pinion, but provides less established fit and material detail than higher-ranked options.

The listing describes a reinforced structure for towing and hauling, pairing that use claim with a 3.73 ratio for GM 8.5 and 8.6 differentials. A 30-spline pinion is also specified, giving buyers another concrete configuration detail when evaluating this gear set for daily commuting or work.

WFLNHB lists compatibility with GM 8.5 and 8.6 differentials, a 3.73 ratio, and a 30-spline pinion, providing several points for identifying the intended setup. Its description says the reinforced structure handles towing, hauling, and commuting, and also claims smooth, quiet operation from gear meshing. The listing recommends professional installation, a practical consideration for planning the job. Buyers should treat the application and spline specifications as central to selecting the set.

Skip it if you need a front-and-rear Jeep package with overhaul kits; Yukon Gear & Axle YGK013 includes both axle sets and master kits.

This may suit a GM 8.5 or 8.6 owner seeking 3.73 gearing for a vehicle used in commuting, towing, or hauling. Account for the stated recommendation for professional installation.

Listed on Amazon as: WFLNHB 3.73 Ratio Ring and Pinion Gear Set 10 Bolt 8.5 8.6 Differential