Orion Subs - How much power?

I have two 10" Orion XTR SVC subs that are about 3-4 years old but still sound great.  I've been running them on an Alpine MRV-T503 amp, which only supplies 75W per channel into 4 ohms.  I bought a new speaker box and when I took my subs out, I noticed that it says right on the back: 4 ohm, 500 Watt RMS.  So, I went out tonight and bought a new Bazooka amp, 500W into 2 ohms.

When I got home, I was looking over the spec sheet that I just got faxed from Orion, and no where on it does it say anything about the RMS rating of the subs.  However, there is a list of all kinds of numbers such as QMS, Qes, RE (ohm), Diameters, etc.  One of the items says Pmax(watts) and it says 500 for my subs.  This leads me to believe that this is the maximum power the subs can handle.  So, am I going to blow my subs by using a 500W amp?  Also, are they going to be okay by wiring them so that the amp only sees 2 ohms?