you'll notice a sucking sound on start up, any air that is cooler/more dense will help, just not sure about performance wise if you will NOTICE any significant gains if you really want to wake up that 3.8, get the following:
Aftermarket down pipe - most restrictive part of the exhaust
Front power log - www.zzperformance.com you really dont need the rear
HVIII- ZZP high velocity intake insert
Home made FWI w/ K&N filter
PCM - www.getoverkilled.ca
you'll really notice a difference with just those, and all of them together will run you $500-800 total. Performance gains of 30+ to the wheels, and i would say better fuel economy, but once you do that, you may develop leadfootitis
Most of them are pretty easy mods to do yourself, you may want to have an exhaust shop do the down pipe though.