What kind of exhaust mani is that kevin? is that a vnt turbo?
Apparently from my readings, the Saab plastic tanks will hold up to ~20psi. In reality? There is no need to go above this number off boost pressure, unless your running some awesome setup to cool that air it is unnecessary heat and hurts performance. Put a strap around it if you want 18-20 reliably.
I´ll have to look out for an all-metal one . My max boost pressure peaks at 28 with vanes fully open. (I don´t have a vane control system setup yet) I guess I´ll be seing higher pressures with faster variations once I get a control system setup.