Sounds to me like you are asking the wrong question or just trying to act smart. A simple, "how much boost on stock internals can a B18A take?", would have sufficed.
Well, in that case, how much boost can a built B18a take?
ATLANTA DA-Squad member #26...[{Home.BASE.Racing}] •R.I.P. LsVtec DB1....hello b20v EF...!•