I have a 1998 2500 suburban with the 454 and 373 rear end. I towed my 31 Sonic every weekend since it was new and I
was very pleased with it. I figure the boat and trailer we were pushing 10,000 lbs.
We recently purchased a Sonic 42 SS and are still hauling with the suburban. I figure the boat and trailer with gear and fuel are close to 15,000 lbs.( slightly overloaded) and we still haul it every weekend with no problem. In fact we can run 70 mph with the air on and seems to have plenty of power thorough the hills. I must ad the trailer has 6 wheel electric brakes, so we have no problem with braking.
The only thing I would beef up is to add air bags to the rear suspension because it does sag a little bit.