40' monaco dynasty is 40' 10". My 42' dynasty is 41' 10". 1' in difference. Bottom line is that 40 doesn't mean 40 and 42 doesn't mean 42. Very few places I can't get into with the tag axles ability to lift with the push of a button. Best advice I heard when I was buying was, "buy the biggest you can afford and buy once"...turned out to be very true for me