I took a look at the all the available floorplans for the 2019 Winnebago Sunstar Motorhome, and I was able to find a couple different variations.
-For the 27PE model, the 72"x75" King mattress was offered,
-For your 290VE, it appears a 75"x60" Queen mattress was offered,
-For the 31BE model, a 75"x60" Queen mattress was offered,
&
Finally, for the 32YE model, a 72"x75" King mattress was offered.
These figures were pulled directly from the official Winnebago Sunseeker brochure, and... view full answer...