We have a 97 Chevy 1500 Express Conversion Van. We have beat the crap out of it year after year. Towing well beyond its capacity (C5Fest towed 9,000 lbs) with a Vortec 5700. it has 185,000 miles on that and fully half of those are heavy towing. The only major thing we have changed on it (years ago) was the transmission since my wife accidentely ran over an object in the driveway and broke it.
Oops...