Need Advice On Actuators

[shanoplata]

Hey all, I was looking for some advice. I have over the past year returned my BA MK2 XR6 TURBO UTE back to standard as the wanker who sold it to me obviously flashed the cars tune to standard to be cheap and sell the X3 before I got it yet left all the mods on the car. I have everything pretty much back to standard but I have a Turbosmart 5psi actuator(adjustable), now when I drive it comes onto boost well but after about 3500rpm boost seems to fade out and power drops. I was wondering if 5 psi if okay as the standard actuator?, I have read on turbosmart's site they recommend their 7psi as a direct factory replacement but isn't 7 psi too much for a standard tune?. I was also wondering where the vacuum line from the blow off valve nipple goes into?. Thank you