yeh youll have to block off the std BOV but thats not a real issue
it will cause some slight problems with fuel mixtures but nothing serious
turbosmarts are very loud and in my opinion rediculous, if youre gunah get an atmo venting BOV go for something a little quieter like a HKS SSQ as the turbosmarts will piss you off after a while, i know the **** me to tears in my mates 180!!