We have a 2014 Greyhawk 31FS. It is actually 31.6 according to the specification sheets. I don't know if that is stem to stern or just the box. I know that the listed width is 100.0" (8' 4") wide but it is actually wider if you count the awning and mirrors.
2004 Chevrolet Silverado 3500 LT with a 2004 Jayco JayFlight 29BHS
2014 Greyhawk 31FS with a 2007 Tahoe toad
2014 Thor Palazzo 33.3 with a 2007 Tahoe toad