The 5.3L in that truck will run forever as long as it is maintained. I know a guy with almost 400K on his company Chevy, and it has spent most of its life towing and hauling. The engine has never been apart.
s10 2.2L (same exact engine in the cavilers) has 167k on it, sounds like a box of marbles in a blender in the morning but goes away once its warm. i havent had to do anything besides a valve cover gasket engine wise. burns maybe 1/4-1/2 qt of oil in 3K miles so i cant complain.