All of the 512 Kb PCMs (Blue / Red connectors) are mutually compatible - whether a 4896 (99-00) or 0411 (01-02) variant. These will operate V6 truck engines, Gen I (Vortec) engines, and Gen III LSx engines (4.8/5.3/5.7/6.0/8.1).

The 1 Mb PCMs (Blue / Green connectors) used from 2003 until 2007 are NOT mutually compatible.