All 2002 Avalanches had the full plastic cladding.
The 2003-2006 Avalanches were available without any lower plastic cladding, or what is known as the WBH or Without Body Hardware option.
The sheet metal for the WBH trucks is different than the cladding equipped trucks, so fenders, hoods and doors and such do not interchange.
The plastic cladding pieces from all 2002-2006 trucks will fit on your 2002.
However, be advised the COLOR of the 2002 plastic cladding is unique for that year only.
The color of the 2002 cladding is a light grey where later years were a much darker grey to nearly black.
Compare the color of your cladding to this picture of my cladded 2003 cladded Avalanche.
If you intend to PAINT your cladding, then the color of your replacement parts will not matter.
But, if you do not intend to paint or if you want to use a restoration product like I did in the above picture, your later year replacement plastic cladding will not look right alongside the OE cladding pieces.