Extended vs standard wheelbase on full-size van

Congrats on the GM 3/4 ton! You should be good up to around 7500 pounds dry. Wheelbase is not a problem as many people have been towing 35' TTs with 3/4 ton SUVs for 15 years. Receiver rating at 1000 pounds is the limit, but many people exceed that.

I recommend flushing all the fluids, a WDH with integrated sway control and Bilstein shocks to help the under-damped suspension.