8 kids - that would be 10 people in the van unless mom and dad are driving separately. ..
I think the base weight of the E-350 is around 6,300 pounds and GVWR 9,600. The 7.3L is about 500 pounds more than a 460" engine, so your curb weight might be as much as 7,000 pounds. With a hitch weight of around 1,000 pounds - see where I am going?
You really need to check the curb weight of the E-350 van. If it is over 7,000 pounds, you really need to check it with all the kids on board, and see what weight capacity you will have left. If less than 1,000 pounds with all the kids on board, you really have been overloading the van - even with a small 5,000 pound travel trailer and 750 pounds of hitch weight. Now you are talking about 1,000 pounds of hitch weight?
Anyway I would take the van and trailer without any kids in it to a CAT scale, or moving company that has a scale, and check the weight. Front and rear axles of the van, plus the trailer axles. Make sure it is not overloaded left to right either. Some trailers have as much as 500 pounds more on the drivers side due to the slide outs, overloading only two of the tires, while the passenger side is escaping being overloaded.
When I checked my motorhome weight at a moving company, I went first in my car, to see where I would enter, cost, and how to move the 30' RV through the crowded area without getting stuck in a place where backing out would be time consuming.
You will either have a GCVWR of 16,000 or 20,000 pounds, depending on the 3.55:1 rear axle ratio or the 4.10:1 rear axle ratio. If you have 4.10 it will either be 22 or 32, 52, 56 for open diff, or limited slip might be B2 or C2 in the axle location on the plackard on your drivers side weight sticker (bottom line, midway right to left).
Hopefully your van is lighter than I think it is. My 2002 E-450 van is 9,600 pounds with 6 kids and me onboard, including a 400 pound wheelchair. I have a 14,050 GVWR and GCVWR of 20,000 pounds with a 4.63:1 rear axle ratio and V10 engine. I an considering a toy hauler that will have a ramp for the electric wheelchair, and that would be around 10,000 pounds, with 1,000 of that on the hitch. No problem for my E-450 based shuttle bus.
Good luck,
Fred.
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