Will be traveling from Hurricane to Mnt Carmel Junction on Utah State Hwy 9 in a 40ft motor home pulling a 25ft car hauler trailer. Notice its a little "windie" in areas. And, are there any "height"...
I've done that tunnel with a 30' bumper pull and it's intense. Even just driving it in my bare dually (no RV) I had to pay extra to stop traffic and drive down the center.
Google Maps shows the other route is more miles but the same elapsed time. It's an interesting drive if you've never done it before.