I have not been on Black Bear for a while but I run it in a bone stock 80 with the stock HWY tires. No issues. The county maintains that road, its really more intimidating than difficult in my opinon anyway. A spotter is a really good thing. As far as the switchbacks. I made most with out any reverse work. 3 point at the most.
You want an early start on that trail so you don't get stuck in a traffic jam waiting to decend into Telluride later in the day.
Any AT style tire should work fine for you here. Very little mud to be seen. Mostly just loose rock. I run Nitto Terra Grapplers right now.
Speski OffRoad LTD, Cargo Solutions for Toyota 4x4's http://www.SpeskiOffRoad.com
"80 series, with a fridge"
1976 FJ40, Project with little progress.
2004 Starcraft 10RT