OMG, it has been so long since I posted on here. Maybe a year?
The DUT3C indicates the Tbred B if I remember correctly. I have gotten the AUIHB up to 2498 on air with a 1.75 vcore. The JUIHB's were initially said to not be as good at overclocking, but a lot of people on here and other sites were able to get just as much out of them as the AUIHB's.
It has been so long, so please forgive me if I am not remembering this stuff correctly.
What kind of cooling are you using?