905 covers the cuse, s 906 covers the serk,s and 08 cuse3
So no heads for the SERKs either. Go figger.
The only thing I can think of is that they've determined that they had more valve guide problems on the CUSE's than on the others. The CUSE's had a much higher rate of leaks too, so maybe that means the CUSE's run hotter head temps which in turn caused more valve guide problems.
I'm sure they're not replacing heads on the CUSE's unless they have no other way to fix a problem. Of course if you have problems, then it will still get fixed under warranty, but they're not replacing heads just for the sake of giving away parts.