My generator space on my class c RV is 28" long. It's the style where you can slide the generator out. Specs for the QG 4000 is 30" long, but the guy I'm buying it from swears it's 28". I think I can bend that side where it slides out 1/4" or 1/2" to make it fit.
I did it! It is 30 at the bottom, but it's less than 29" 9" from the bottom, which is where my tray was smaller. The compartment is huge, I just had to make the tray work.