I'm pretty sure you have a 10,000# hitch on your coach. As long as that is the case and you do not exceed the GCWR, you will be fine. The ISB 300hp will know it's back there and the mountains/hills will slow you down a bit more, but it will do the job. I used to tow a 4800# toad with an ISB 275hp in a 39' Bounder with no problems.
2013 43 QGP Allegro Bus
CJ7 Rock Crawler