I have prolly towed around 5000 once. I have a 4x4 4wheeler and my toyota pickup on my 16foot trailer. plus all my camping gear. how i had to position the 4wheeler and truck ended up putting to much tounge wieght on the trailer for the rear suspension. the drive train did great. without the 4wheeler on the trailer the s10 does just fine towing the yoyo pickup. ANd even better since i helper air bag springs.
I have a 2000 4x4 w/4.3. I've pulled an 88 Grand prix with a dual axle open car hauler. Looked up the weight on the car and it was 3,100 lbs. the trailer is an easy 1,000. Position is everything to not squashing your suspension... Drivetrain will pull anything!