The stock ls motor will handle more then the jrsc unit can probably dish out on your ls.

Your biggest issue is going to be fighting heat which will lead to detonation.
JRSC setups run very hot intake air temperatures. With this in mind, I suggest you get your self an LHT jrsc cooler.

Another vital issue is tuning. You are going to need the proper sized injectors, fuel pump & fuel management system.

Honestly I am not a big fan of JRSC setups. By the time you buy the JRSC, install it, buy a cooling system, a nice header etc... you are already in the range of a turbo charged setup that will yield much more potential.