Help Me --Will I blow my system?

Hello, This is a newbie question so I am sorry if it has come many times before. I just bought some amazing Legacy Studio monitors that run at 4 ohm impedence and have a peak rating of 300w. I want to run them with a B&K sonata ex 442, which runs at 200w each channel at 8 ohm. This means though that the speakerrs will be at 400 w at 4 ohm, which is 100w over the tech Legacy rating. Is my B&K to powerful? I have another system the Legacy's can go on, but I was hoping to use it on my B&K system. It should be noted that I have blown a pair of Polk Audios with the B&K, but I heard that Polks just blow with any set up. ( I am very careful though.) I guess this is a 4 ohm v 8 ohm question, one that still escapes me, as I am not so sure what 8/4 rating even means in a real world of listening.
No. Use the B&K, it won't be a problem unless you really crank the volume. (really, really crank it!).
Absolutely no problem unless you try to blow your walls down with the sound. Good luck and welcome.
It is more likely to blow a speaker using too little power then using more than you need, I doubt you will ever be able to tolerate the levels it would take to blow those speakers, also the speaker should indicate when it is being pushed too hard....then just turn it down a bit.
Volume and power don't have a linear relationship. The smallest increase in volume the ear can perceive is about 3dB. Raising the volume 3dB requires DOUBLE the power from your amp. And doubling a given volume requires TEN times the power from your power amp. Sudden loud passages can require A LOT of power from an amp. Your speakers should be quite happy with a 400 watt amp. Driving any speaker to distortion, clipping the amp, will damage most speakers. But way short of that, your 400watts will be put to good use.
Are you sure the amp is rated for 400 Watts at 4 ohms? Don't assume that power output doubles as the resistance is halved - check the owners' manual spec section to see what the power actually is. And even if it is 400W, I also agree that you won't damage your speakers at normal loud listening levels.
Clean power won't ever hurt a speaker unless you are getting into deafening levels. You are going to be deaf if you try to listen to your speakers at 300 watts continuosly. You may get peaks (canon blasts, explosions...) that will test your system. However, as long as the amp is distortion free, you are safe. It doesn't get much cleaner than B&K.
FWIW, the EX442 is actually rated 350W @4 ohms.
Thank you all so much!