If the engine is detonating bad enough to blow a piston, the head studs are really irrelevant. Zeus is simply saying that not upgrading your head studs to ARP's because you are worried about tossing a piston is pretty dumb. ARP's are good insurance, especially for high boost, and everyone assumes the car is tuned to handle the boost.

 

In all of my babbling, I forgot to answer the original question... 23psi with 94 octane is just fine as long as you dont have your friends sister tune it. Even with a stock ECU its fine.

 

I wouldn't assume that your custom dynoflash on your car has conservative enough timing to allow for the extra boost. What boost were you tuned on? If you were tuned for 22, then you are probably okay, but if you were tuned on less than that or if Al tuned you right to the edge for 94 octane on lower boost, it might be close to the edge at 23 psi. The fact that you taper to 19 isn't too important. If you are going to have detonation issues, they would most likely be in the mid-range at peak torque with the added boost.