[lazylongboarder]

Anytime you add more Air,Fuel,or Spark you will see improvements in performance. But at the same time beware of opening them up too much. Stock heads are known to crack. Also another caution is the actual tuning of changing the port size on a head. You need to have other things that will utilize that extra volume in the ports (A.K.A more air and fuel). Larger carbs or if injected, larger fuel pump and injecters. Don't use the stock mechanical fuel pump.

Don't forget about a cam to "use up" the larger port size. The more aggressive the grind on the cam, the longer the valves are open to allow more air/fuel into the combustion chambers.

Good luck

Russ