I ran my JVC for a few years with the stockers in, 15 watts rms 35 peak, never blew a speaker. This is because for it to be loud enough to make 15 w/ch it sounded so much like azz it's not funny. I bought a pair of sound storm labs 5702's off of ubid a few months ago, not very good, but better than the stock speakers and at something like 15/pr shipped the deal was right.
Don't worry about blowing them, if you do that is more reason to buy better equipment
-Pete