They usually are pretty universal meaning a cover that fits a 30' motorhome, should also fit a 33' motorhome. With that being said, I did some research on your 2006 Gulf Stream Endura, and I found that the lengths of this motorhome spans from 32'-11" to 36'-11; and are 11'-10.5" tall. Our largest cover for motorhomes, # 290-52845, only supports motorhomes up to 32' long, as well as up to 114" tall. Your motorhome, however, measures 142.5" tall.
To be certain though, I recommend measuring... view full answer...