On pd blowers I think 8 or 9 psi is about tops with the stock l99 cam. Much more and you have too much boost at the peak torque and detonation is too hard to avoid without giving up more power than its worth. That's why I went centri. 7 psi peak torque, 13 psi at 6200 rpm redline and all is good.
I think you should invest ID 850's, the fuel rail mod, ZL1 pump, ADM FPCM, and then push 8 or 9 psi. You will love the power once the tune is on and You have plenty of fuel supply.
2011 SS IOM Vert. ECS Vortech Si, 12.5 psi (13 when spraying), JRE 2800 stall, LT headers, Catless, Zex 125 shot, LNC2000, Innovate Wideband, ID-850's, ZL1 pump, ADM FPCM, MSD BAP, Nitto 555R's, I hack it up, Ted tunes it in.