Actually the 2008 Quigley's have 8x170 just like the F350. My tire guy didn't believe it either, but it's true. They also require 17" rims minimum to clear the larger brake rotors.
2008 Ford E-350 Quigley 4x4 V10 - 164,000 miles
RB50, PH Top, Dual AGM Group 27 Deka, 2000 Tripplite Inv., No Propane or Water Systems
Van Weight 8,100 pounds, added one rear leaf spring, BFG AT KO LT265/70R17 E Tire press 50psi.