I towed two different TTs with my 89 Astro LT with tow pkg (3.73 rear end, engine oil cooler, HD radiator) the first was a 20'Komfort with a GVWR of 3800 lbs and the second was a 21' Trail Lite with a 4000 GVWR. Both TTs were easily handled by the Astro - which I traded for a Tahoe in '99. The CGWR of the Astro is 10,000 lbs and the tow rating was 5000 (89 version). My Brother in law tows a lighter weight 80's something Prowler with their Envoy. I would think that you would be much happier with a larger tow vehicle - esp when you get into the mountains.
07 Chevy 2500HD 6.0L ,6 speed auto, 4x4, Blue Granite Metalic
05 Arctic Fox 22H