Sure man, glad I can help out....

I cannot tell you definitively what boost is safe for you... It is a function of a whole slew of parameters, such as engine part material, flow characteristics of the intake and exhaust paths, etc...

You will need to do a thermodynamic analysis of your setup in order to theoretically know your maximum boost pressure (this can be done online now)...

Basically, you need to avoid detonation... If you don't know what this is, Google it...

You can also inquire about your setup, as it seems alot of people use that turbo for B-series turbo builds (cause it is most efficient where the torque peak of the motor is, aka high rpms) and see what they are running...

But what works for one may not work for you, so use caution....