Mountain driving and towing with a gas class A

We had an Infinity 38 foot MH with the Ford V-10, and always towed either a Chevy S-10 or Jeep Liberty.
Can't say we did ALL the passes, but we traveled all over the western US and parts of Canada for 5 years. My wife would sometimes say on the way up, "are we going to make it?".
We always did, and had a great time.