FilthyMotorsports.com

Gear Ratio Recommendations Tire Size Highway OEM Towing 31" to 33" 3.08 3.42 3.73 34" to 36" 3.73 4.11 4.56 37" to 39" 4.56 4.88 5.13 Gear Ratio Calculator Engine RPM Calculator

Locker Recommendations Chevy 1500 series trucks feature an aluminum "clam shell" style front IFS differential. While gears can be replaced to account for larger tire sizes, we do not recommend lockers for the front of these trucks. For the rear, we highly recommend the Eaton TrueTrac for most applications or an OX Locker for extreme off-road use.

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Chevy Silverado / GMC Sierra 1500 (1999-2007)

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The following gears, lockers and install kits are available for 1999-2007 Chevy Silverado and GMC Sierra 1500 Series Trucks with GM 8.25" IFS front axles and GM 8.6" or GM 9.5" rear axles.

Front: GM 8.25" IFS 28 Spline (IFS) No Carrier Break Reverse Rotation Due to the limited strength of the GM 8.25" IFS axle housing, lockers are not recommended for this application.

Rear: GM 8.6" 10-Bolt 30 Spline C-Clip 2.56/2.73 Carrier Break Standard Rotation OX Locker Eaton E-Locker Eaton TrueTrac Rear: GM 9.5" 14-Bolt 33 Spline C-Clip No Carrier Break Standard Rotation Rear: Dana 60 Quadrasteer 2002 - 2005 4 Wheel Steer

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Chevy Silverado / GMC Sierra 1500 (2007-2013)

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The following gears, lockers and install kits are available for 2007-2013 Chevy Silverado and GMC Sierra 1500 Series Trucks with GM 8.25" IFS front axles and GM 8.6" or GM 9.5" rear axles.

Front: GM 8.25" IFS 28 Spline (IFS) No Carrier Break Reverse Rotation Due to the limited strength of the GM 8.25" IFS axle housing, lockers are not recommended for this application. In 2010, the GM 8.25" aluminum housing changed, but all of the internal parts remain the same.

Rear: GM 8.6" 10-Bolt 30 Spline C-Clip 2.56/2.73 Carrier Break Standard Rotation OX Locker Eaton E-Locker Eaton TrueTrac 2009 and newer GM 8.6" axles use a different pinion bearings and pinion seals. Rear: GM 9.5" 14-Bolt 33 Spline C-Clip No Carrier Break Standard Rotation

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Chevy Silverado / GMC Sierra 1500 (2014-2019)

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The following gears, lockers and install kits are available for 2014 to 2019 Chevy Silverado and GMC Sierra 1500 Series Trucks with GM 8.25" IFS front axles and GM 8.6", GM 9.5", or GM 9.76" rear axles.

Front: GM 8.25" IFS 28 Spline (IFS) No Carrier Break Reverse Rotation Due to the limited strength of the GM 8.25" IFS axle housing, lockers are not recommended for this application.

Rear: GM 8.6" 10-Bolt 30 Spline C-Clip 2.56/2.73 Carrier Break Standard Rotation OX Locker Eaton E-Locker Eaton TrueTrac Rear: GM 9.5" 12-Bolt (5.3L V8) 33 Spline C-Clip 3.23 / 3.42 Carrier Break Standard Rotation Rear: GM 9.76" 12-Bolt (6.2L V8 and/or Tow Package) 33 Spline C-Clip 3.23 / 3.42 Carrier Break Standard Rotation