If you are doing a 12hr race maybe see about the Proline knuckle 2.0 if it's still made. You could also put the cuts like Chad Bradley and Mark Pavidis use to do.
I think the compound is a individual thing. There are a bunch of things that help make-up the choice of tire. I ran a set of Crimefighters XTR when others said they weren't the best tire. I TQ'd. I used them when it was what I felt was hot. I noticed it felt like other tires were almost greasy feeling. I thought the softer compound was getting to hot and I was loosing traction. So I went to the harder compound. Good Luck!