Okay so I bought 2 Pioneer GM-7300M mono channel amps and 2 Pioneer 12's in a custom box from a friend who had it hooked up in a Tahoe. They each have 360 watts RMS and 800 max.

The question I have is does the alternator in the CL push out enough amps to power both of these or should I get a cap or an aftermarket alternator? Or would the stock alternator be fine? It was fine in his truck but seeing as how that is a beast of an engine compared to ours the alternator has to be pushing alot more amps than the CL.

 

The CLS has a 130amp alt stock. Most GM trucks have the same. Run a cap & you should be fine. If you have problems after that then look at upgrades. (Alt, 2nd battery, etc)
Also run 1-2 gauge wire to a distribution block then 4 gauge to the amps.