FYI...I just stopped and talked to a guy with an E350 Chateau Van with 265/75/16 tires on it. Stock E350 with no suspension alteration. The tires had plenty of clearance in the rear. The front looked a little snug but it cleared. He said he had to do some minor front trimming on the gray cowl. He said it doesn't rub at wheel lock and only rubs the front plastic if the wheel is turned all the way and he hits a big bump.

 

Grant,

Thanks for talking to the the guy and checking this out. It is great to know that it will fit on a stock E350 Chateau.

Keep rolling,
Steven

 

How about:

1. Changing springs in the rear to E150 spec
2. Adding air bags/springs to rear to add load capacity as needed

My reasoning behind this is; I have an e350 28' Metrotrans shuttle bus. They used an E350 because they outfitted it with a third rear axle which is setup just like commercial buses, it has a single wheel and is full air suspension. With this setup the ride when there is no load or only a partial load is actually quite smooth. To accommodate 25 passengers plus baggage I simply press a button to activate the compressed air to handle the extra load. This thing glides down the highway far smoother than I could have imagined.

The company I work for has shuttle buses running around campus all day and I've noticed they ride super stiff like there is no suspension at all. I've ridden them many times over the years to attend meetings in other buildings and when they hit a bump, it's super stiff. They are much smaller than my bus and are built on E450 chassis. I bought the shuttle for family road trips.

 

I was all set to preform a 1.5-2" lift in the front of my E350. I had the springs all lined up. I kept getting conflicting results from front end shops of if a minor lift would be possible with stock i-beams/radius arms. Overall advice i got was it would work, but going away from stock is going way from ideal, and front tire wear will be an issue to some degree.
Instead, along the lines of Ehbrah's idea:
-I took my 2006 E350 w stock Michelin's 225/75 r16's
Switched to Michelin 245/75 R16's (after trying tires from remington that were horrible! They rode stiffer around town, and dangerously swayed more on the freeway at speeds, and they were E-rated tires!)
I have a buddy that has d-rated 265-70-16's goodyears, and he says it rides great, but I wanted to stick with e-rated for the sway at speed reason.
Michelins are worth the money!!
I knew a 265/75-r16 would fit, but the E350 vans I have seen looked as if the tires were too tight in the front.
-I had a company Deaver Springs (local shop in anaheim, ca known for building custom leaf springs), take my stock e350 leaf springs out de-arch them 1 1/2". Now my van sits near level, still has the e350 springs, rides softer, and still has close to the load capacity of an e350. My van rides noticeably less bouncy and feels more active and supple. It feels like if i were to tow, it may require airshocks to assist.
The optical illusion is now that the van is near level, it almost looks as if it was lifted.
I am very pleased with the improved ride quality and results.