I had several 1989 B250 standard wheelbase vans. They were 318/518 with 323 gears.5 lug axles.The vans were loaded down with maybe 7-900 lbs of HVAC stuff on the shelves inside.

I had a 1600 lb tandem flat bed trailer that was used to pull HVAC equipment or a 2500 lb manlift around.

The trailer had brakes on one axle and no WD hitch.It took your full attention to load the trailer properly so the load was over the axles. When driving it was the same deal, watch the road ahead, border line white knuckles.

I did it back then out of necessity, I can't say I'd like to do it again.

Does the van you're considering have the 8 lug or 5 lug GVW rating? I'm guessing with that gear 5 lugs. I wouldn't waste the money on a 5 lug, but if you do, the gears gotta go.

You might be better to look at a mini motorhome with a dually rear. I had a 71 Dodge back in the day with a 318/4.10 rear. I pulled a 3000ish lb boat all over with it and it was a good setup.