wingnuts-
Winnebago has a Web page for product information
here.
The brochure for the 2001 Itasca Sunrise is
here.
That brochure says the 2001 Sunrise 30W is built on an 18,000-pound GVWR Workhorse chassis. The certification label on the coach should confirm (or not confirm) that. If you have the VIN you might be able to get the chassis rating from that, too.