Classe CA200 & KEF 104.2's

I have had this system up-and-running for a couple months now. Speakers are biwireable and I am using the CP-35 preamp. I know this amp puts out a very clean 200 watts per channel into 8 ohms and 400 watts into 4 ohms. These are 4 ohm speakers; therefore, I have never taken them past 25 on the preamp volume meter (which goes to 60).
Question loud can I take these speakers without the risk of blowing something?
I wouldn't worry about blowing the speakers. I have the same bi-wired Kef 104.2s and have used a Bryton 4B NRB that puts out 250WPC into 8 ohms and 400WPC into 4 ohms. I've pushed the volume to ear-splitting levels without a problem.

In general, the better the amp, the less likelihood of clipping which would potentially damage your speakers.