Our "usual" mowing truck is a 05 Silverado with a 4.3L v6 and auto trans. It pulls a 10x6 open trailer that weighs 1,050 lbs. On the trailer is a JD 647A that weighs 1,014 lbs, a Honda commercial push, two Stihl Kombi's, a Stihl blower, 5 gallon gas can, 2.5 gallon gas can, and racks for everything. We haven't had any problems. I wouldn't go 80 mph with this combination, but it gets us around town and to the next town over which is 5 miles of highway.
Our leaf cleanup truck is a 67 Chevy C30 with a 292 inline 6 and a 4-speed, but that isn't even in the same realm. That truck could pull a barn over.