I have a 2005 Fleetwood 39S with the Cat C7, 350 and similar weights. Have been up and down the AlCan, over the Continental divide I don't know how many times. I'm pulling a 2002 Jeep Wrangler. As long as you pay attention to your driving, the C7 350 does just fine.
And what do I mean by paying attention to your driving? Little things like pay attention to the upcoming hills, make sure you're not loafing along at 45mph and 1500rpms when you start up the hill. That will kill you every time. Pay attention to the traffic in front of you. Often the trucks will pass you on the flats and then bog out on the hills. If they're bogged down and it's going to cause you to slow down and drop out of your power RPMs, then pass them. You'll often outpull the trucks if they're loaded. If they want to go faster out on the flats again, let them pass you. Learn where your rpm power bands are.
The transmission is fine. Make sure it has Transyn fluid in it. If it's never been changed, change it and they you should never have to worry about it.
Get the radiator cleaned and make sure the slobber tube extends out beyond the radiator and you shouldn't have any overheating problems. Mine never has.
Bill
