I. OE Replacement Part:
NP261XHD, RTC261GXHD1
24228406, 12579907, 12581002, 12588514, 15023641
15772804, 24238186, 24238839, 412458
412542, 412604, 412-542

II. Compatibility:
Replacement for Chevy Silverado 2500 HD 2001-2006
Replacement for Chevy Silverado 2500 HD Classic 2007
Replacement for Chevy Silverado 3500 Classic 2007
Replacement for GMC Sierra 2500 HD 2001-2006
Replacement for GMC Sierra 2500 HD Classic 2007
Replacement for GMC Sierra 3500 Classic 2007

III. Note:
Gear Oil Type: 75W-90
Fits 2001-2007 GM Trucks with RPO code NP2. This is the manual shift unit for GM trucks with the 6.6L & 8.1L engines.
Input Shaft (Internal Spline): 29
Front Output: 32 (Internal Spline, one tooth missing)
Rear Output (External Spline): 31

Thank you for your purchase of our Transfer case. Before installation, please be sure to add gear oil to the transfer case. Failure to add gear oil before installation can damage the product and may lead to premature failure. Please note that we will not accept returns or claims for products that have been damaged due to improper installation.