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(520) 327-1747  |   info@westerndiff.com  | 3825 E Kleindale Rd Tucson, AZ 85716

Custom GM 12 Bolt

Custom GM 12 Bolt Differentials are built to order

Custom GM 12 Bolt (8.875") Car

Western Differential can customize New GM 12 Bolt housings casted from Nodular Iron from either Currie Enterprises, Strange Engineering or Moser Engineering. We can also rebuild or upgrade an existing GM 12 Bolt Factory housing.

  • 1962-67 Nova (mono-leaf)
  • 1968-76 Nova (mono-leaf)
  • 1968-76 Nova (multi-leaf)
  • 1967-69 Camaro/Firebird (mono-leaf)
  • 1967-69 Camaro/Firebird (multi-leaf)
  • 1970-81 Camaro/Firebird (mono-leaf)
  • 1970-81 Camaro/Firebird (multi-leaf)
  • 1982-92 Camaro/Firebird
  • 1993-02 Camaro/Firebird
  • 1964-67 GM A-Body
  • 1968-72 GM A-Body
  • 1978-87 G-Body (Grand National)
  • 1955-57 Chevy
  • 1965-70 Impala
  • For Other Car Applications Please Give Us A Call At (520)-327-1747

Gear Ratio Options: 3.08, 3.31, 3.42, 3.55, 3.73, 3.90, 4.11, 4.30, 4.88 or 5.14

Carrier Changes: 2.73 & Down, 3.07 to 3.90, 4.11& Up

Carrier Options:

  • 30 Spline - Auburn Posi, Detroit Locker (3.08 to 3.90), Eaton Posi, TrueTrac (3.08 to 3.90) or Spool (Non-Street Vehicles)
  • 33 Spline - Auburn Pro, Detroit Locker (3.08 to 3.90), TrueTrac or Spool (Non-Street Vehicles)
  • 35 Spline - Detroit Locker (3.08 to 3.90), WaveTrac or Spool (Non-Street Vehicles)

New or Rebuilt GM 12 Bolt (8.875") Truck

Western Differential can customize New GM 12 Bolt housings casted from Nodular Iron from Moser Engineering for the applications below. We can also rebuild or upgrade an exisiting GM 12 Bolt Factory housing. 

  • 1960-62 Chevy C10 Pickup 
  • 1963-69 Chevy C10 Pickup
  • 1970-72 Chevy C10 Pickup

Gear Ratio Options: 3.08, 3.42, 3.73, 4.11, 4.56, 4.88, 5.13 or 5.38

Carrier Changes: 2.73 & Down, 2.76 to 3.42, 3.73 & Up

Carrier Option:

  • 30 Spline - ARB Air Locker (3.73 & Up), Auburn Ected Locker or Detroit Locker (3.73 & Up)

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