If it says "stock only", they are not manufacturing any more. Our model (374FL and 375FL) went out of business 2 years ago and was replaced with the 376FL and 377 FL. They took the 374-375 and beefed it up a bit, by adding a stair way and a loft. Probably, 382 and 383 will be replaced with something very similar, but something different, enough difference it makes it a completely new model.
Who you are right now is a sum total off all you use to be.
2019 Montana High Country 375FL
2014 Chevy Silverado Duramax, 6.6L Dually