My dad has pretty close to the same set-up as you coach, trailer and engine. He has to run 91 so it doesn't ping when climbing hills. That said, Banks has an awesome Power Pak for the V10. Headers (Banks calls Torque Tubes), y-pipe, cat-back exhaust, cold air intake, engine computer, and tranny computer for around $2100, it claims 53hp and 69ft-lbs torque which is about as good as you're gonna get on a gas engine. The problem is they say you need to run 91 octane. So if those changes require higher octane will you need even more to keep it from pinging. Hope some octane booster will take care of it. I also have a V10 (Excursion) but my dad and I can't justify over $2000, almost $3000 if you have it installed for a little more power. Oh, and Banks says you could get maybe 1-2mpg increase if you keep your foot out of it but that's impossible with all the weight you're pulling with RV and trailer. My dad gets around 8-9mpg when lightly loaded crusing 60mph and around 6mpg when loaded and running 70mph. His RV is a 2001 Jayco class-C 27ft with the V10.