Get a boost controller and boost gage. You will at the very least blow a head gasket if you routinely go over 16 psi. Even worse you may damage the case and or burn a piston or valve that could be sucked into the engine. These are fairly expensive repairs. The boost controller and gage would set you back less than $150. Cheap insurance.
On the other hand, if you are track racing and don't need to drive the thing on the highway then boost the hell out of it and wait for something to blow!