Hey guys... hopefully some of you are more up on your electronics engineering than myself, as it's been a while since I've done this stuff. Anyway... Question;

I have an 200W 8 ohm impedence, 3.6 ohms DC resistance speaker. I have a 280W Amp. The power rating on the amp is at 4 ohms. Someone who recalls calculations involving impedence and all that jazz help me out, what kind of power would the amp be feeding that speaker? Do I need to worry about blowing the speaker, or can I crank it fearlessly?
I'm pretty confident the amp will remain stable, as it's designed to be stable at 2 or 4ohms, and it's a high current amp. Any help?