Theres several way's of doing it. Spoke to Nick recently.
1) You can replace the n75 with mbc.
2) You can link it in series from the charge pipe to control the max boost.
3) You can link it in parallel to control the spike.
I went for the second option as shown here:
Third option is like so:
Just need a new boost gauge, my digital one that runs of a sensor is sh!te, I don't mind a psi or two out in accuracy, but this thing thinks i'm spiking at 28psi on a k03 and when stationary and off it sometimes assumes I'm doing 10psi. I'm on my 2nd digital sensor as well that the vendor sent free of charge

Reference:
http://www.boostvalve.com/1.8.html