Here's all the Gutter part#'s for an 02. They should be the same up to at least 07. Go to gmpartsgiant.com, put you VIN # in and it will show you all the parts for your truck.... These prices are from gmpartsdirect because they are usually a little cheaper. Cost may have changed since I looked theses up..
PN -15078543 Front right $7.06
PN -15078542 Front left $7.37
PN -20787413 Center right side $23.79
PN -20787412 Center left side $23.76
PN -15090199 Rear right $11.24
PN -15090198 Rear left $11.24
www.gmpartsdirect.com
Randy