dude youll be 100% fine especially if your subs are in a sealed box. speakers blow the majority of the time due to distortion of the audio signal by a crappy amplifier or one that is being pushed beyond its limits (ie gain set too high, ultra low input voltage) causing heat to become built up in the internals of the speaker. as long as the gains are set as a reasonable level you shouldnt blow your subs. youll hear them start to sound like crap (when the speakers are being pushed beyond their capacity) before you ever blow them.

i competed in 3 different classes in DB drag for 8 years and installed for 10.

also dont get too caught up in your amp being rated for 500 rms. odds are that number was taken at 14.4 volts which is only a benchmark rather than a true rating of what youll be getting while you drive your car. most of the time your amp will be seeing power in the 13 volt range therefore less than the rated power.

also to note, depending on the brand of subs you have, the quality manufacturers typically under rate their products to avoid replacing their products under warranty and since much of their sales are inluenced on customer satisfaction, blown speakers are bad news.

my JL13w7 was in a vented box getting 500 rms more than it was rated for and never had an issue. while this is a beefy sonuva bitch of a speaker, the idea is the same that your speakers while rated for 150 RMS should not have a problem taking anywhere up to 200 without a problem.

youre fine. good luck and enjoy

 

I actually like the stock radio head unit in the new Silverados and would like to keep mine in and run subs off it if possible.