If you want a 4.3, get a 2014 or later model. Those are around 300 hp and lbs of torque. This is a redesigned 4.3 vs the 2013 and earlier models, as noted a 350 with 2 cylinders lopped off. I had a tbi and a vortec version in Astro vans. The vortec was a beast vs the tbi. Still, I would not want to tow over about 4-5000 lbs with it. I've been looking at the 14 and newer ones. With the 6sp auto, It would do ok with upwards of 6-7000 lbs. Won't be the quickest thing on the block, but still do what I would call, reasonably well.
Marty