2009 Silverado LS, 6.0l, 6sp, 4x4, extended cab, 8' box. I towed a Jayco 321RSTS which had a GVW of 12,500 (we usually towed lighter but were probably close on a 3 month Alaska trip). Max tow rating for the Chevy was 12,300. It was the work truck model which meant more payload capacity that loaded models.
It towed the Jayco very well. As others have said, when climbing you have to just let the 6.0 liter rev.
Towed through MT & ID which has some long interstate climbs and all the way up the Alcan & Back the Cassiar with no problems. The Chev 6.0 handled it well.
