I don't like running an injector past 85%, just asking for trouble in my opinion. Where is your base fuel pressure? I know when I had the 160lb injectors in mine we had the base fuel pressure right at 60 psi and with 1:1 rising rate regulator saw just under 95 psi under 30+ psi of boost and still went 100% static on the injectors. So long as the max fuel pressure stays under 100psi you shouldn't have any trouble locking up the injectors. I just switched to Morans 235 and with 42 psi base fuel pressure I'm only 72% duty cycle under the same boost. Changing injectors did not net more hp, just made the fuel consumption controllable. With an injector static you basically have your fingers crossed hoping everything works, you no longer have it under full control..
That motor must like timing at 27*! I would be curious to see the plugs after a pass. I know Bruder Bros. run close to 30* in there car but I don't have their budget. We haven't had more that 21* in my motor yet and only seeing 90* IAT's