New Michelin LTX M/S2 Dually clearance issue??

You could change over, if financially feasible, to the Michelin XPS Traction tire in the same 215/85R16 size.

I believe these have a stiffer sidewall, and from reports I have seen here on the forum, users are very satisfied with these particular tires.

Most any other size will rub for sure on the 2003. I previously owned a 2003 Chevy dually, and observed a friends vehicle (also a 2003) with 235 sized tires and they rubbed unloaded.