What's the longest/heaviest you would tow with a 1/2 ton?

Tbh, anything new should do a better job. I was surprised you avalanche preformed so well, i had the 5.3 in my 2012 seirra ( i think?) But then i remembered i think it was the new fule economy standerds that auto shifted the cylinders in the engine that i think was my problem. They took a second or more to respond to the gas pedal. I think they will have worked that out by now. The 2500s dont have the need to hit mpg standerds so no throttling.