263XHD Transfer Case Specifications: - 263XHD Transfer Case - 29 Input Splines - 31 Output Splines (Rear) - 32 Output Splines (Front) - Compatible with 6.6 Diesel Duramax and 8.1 Gas Engine - Bolts Up to Allison Transmissions and ZF6 Manuals - Electronic shift transfer case for push button 4WD control on the dash OE Numbers: 24228417, 12575648, 12576352, 12579909, 12581004, 12584758, 12585237, 12588516, 15005450, 15057935, 15772805, 24228411, 24238188, 24238841, 412456, 12573382, 412-540, NP263XHD, 263XHD, NP263, NP 263 XHD Compatible Models: - SILVERADO 2500 2001-2006 - SILVERADO 2500 CLASSIC 2007 - SILVERADO 3500 2001-2006 - SILVERADO 3500 CLASSIC 2007 - SIERRA 2500 HD 2001-2006 - SIERRA 2500 CLASSIC 2007 - SIERRA 3500 HD 2001-2006 - SIERRA 3500 CLASSIC 2007 Compatibility Disclaimer: This is an aftermarket replacement part.Any brand names or model designations mentioned are used solely for the purpose of demonstrating compatibility.