39 hours on that one mapped out version isn't even close to realistic on a bike. That's 60mph average for 39 hours. I was kicking ass riding from NY to Colorado mostly on interstate last year and that took 4 days and every day was around 12 hours of riding. I smoke though so there's one extra stop every tankful.
For comparison I rode from upstate NY to NW Arkansas this past spring, around 2K miles the way I went. I did the scenic WV roads and also hit the Smokies on the way. That was a 4 day trip and it seemed like I was riding the better part of every day. That's the result of riding scenic twisty motorcycle roads.
Best way to do your trip in 3 days will be all interstate and never stopping to take in anything along the way. It can be done but if you don't have to rush it'd be way more fun taking a week. Lot's of good stuff if you can work the Ozarks/Smokies and WV into the mix.
― Tom Waits
Don't you know there ain't no devil, it's just God when he's drunk.