Hello All, I am going to jump in on this convo if it is ok. I have a few questions of my own. I have a 2009 Chevy Sis - burban. It contains a 5.3 with a 3.08 rear gear. It has a CGVWR of 11000 lbs, and GVWR of 7200 lbs. I am now a math professor, by my calc that is a 3800 lbs trailer With stuff inside at the maximum rating. Minniemom and I want to go with a Hybrid (Rockwood Roo 233S.) If I change the rear gearing to a 3.42, with the same engine I go up 500 lbs. The Sis - burban has a tow mode and a trans cooler in place already. What can I do to get 2000 lbs more towing capacity out of the Sis