My fist new truck had a 292 I6 with whopping 105 hp. A bb v8 at the time did not even have but 200 hp. A v6 pushing out 300 hp should be able to move MANY trailers that some say they could not. I move 5k trailers with the 292. Not fast, but fast enough. Folks today do not see motto wantthe motors to rev so they make the rrated hp. I have no issues having my vortec350 into the 4-5 k range so it can make the 200-255 hp it is rated at. Pulled a 12k trailer from a stop up a 2-3% grade to 45 mph @ 45 mph on 2nd gear. A people geared v6 with equality hp should be able t do the same.
Oh, that 292 was in an 8600 gvw2500 GMC. I can hear the howling on a barely 100 hp motor in a typical 3/4 to. Truck. Much less getting the same motor in 20k v60 series truck.