Wasn't this topic addressed for you in this thread that you started? > http://bansheehq.com/forums/index.php?showtopic=171549#entry1543512
The long and short of it is this > If the "buddy" you have porting your cyls can't answer this for you, why use him? Its obvious they don't know what they are doing or you wouldn't be asking... so why not save your money, and send it to a reputable builder that can answer your questions about the motor? Its going to bite you in the wallet if you don't.