FixVault

Rear Axle Usage

WARNING: This page is about a different car, the 2006 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Serial Number And GM Part Number
GM1491402Courtesy of GENERAL MOTORS CORP.
Callout Component Name
1 Serial Number
2 GM Part Number
Available Axle Ratios

GM P/N Axle Ratio Transmission
12583198 3.42 Manual
12583199 3.42 (with cooler) Manual
12574657 3.42 (Z06) Manual
12583200 2.56 Automatic
12590206 2.56 (with cooler) Automatic