I have no where close to the money to buy a new O2 housing but I'm trying to get every last bit of power out of my setup that I can. Does anyone know how much metal I can take out if I port the stock o2 housing... I've ported stuff before cause I work in an engine shop... I just wanted to know everyone's opinion on how much porting might help with just a cat-back exhaust...

 

match the gasket.