The following Nerf Bars were designed to fit your GMC C/K 2500:
Aries Nerf Bars- $177.95
Dee Zee Nerf Bars- $203.35
Lund StepRails Elliptical Aluminum Side Steps with Mounting Bracket- $337.95
Smittybilt Sure-Step Nerf Bars- $171.95
Steelcraft 3" Round Step Nerf Bars- $169.95
Westin E-Series Nerf Bars- $188.95
Westin Signature Series Nerf Bars- $217.95
Model years for C/K 2500 nerf bars include 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000, 1999 and earlier.