what is the correct torque?
 

what is the correct torque to tighten the wheel nuts on a 2003 silverado ss?

140ft/lbs

That much? The nuts become stuck very quickly when I after changing wheels. Can't loosen with the same air-impact-tool I use to gently tighten nuts, need long tool and a 3 foot pipe to losen the nuts again.
My Caddy only need 100 ft/lbs.
But I'll take your word for it, its a heavy truck with lots of "push"!

maybe they were over torqued.

your caddy uses 12mm studs the truck uses 14mm studs.

do not put any anti seize compound or lubricant on the studs