no power adder, no tune, your probably looking at an slightly better airflow getting to the combustion chamber a little bit quicker, so probably no real power difference, but maybe a slightly better throttle response depending on how rough the stock one was. porting and polishing is more or less a way of squeazing any possible amount of efficiency out of your setup when you are already pushing it to its limits. I would put the money elsewhere first if your looking for power increase.
2002 GT 5sp. 16x,xxx miles
Steeda Exhaust, C&L plenum, BBK Throttle Body, Steeda Underdrive, Steeda short throw, unknown stage clutch. Rear main leak. Compressor seal leak. Steeda lower control arms. good tires.