You will use the 6" crank pulley along with a 3.33 sc pulley most likely...this will yield about 9.5-10psi...If you end up needing a bit more you can go to a 3.2x sc pulley or if you end up a little over you can go to a 3.43 sc pulley (you probably already have this size...so you will probably end up at 3.33).
I explained the misunderstanding about there being no "adjustable size" pulley in my pm.
So...You need to add the 6" crank pullet I sell...=+3psi!
Paypal away...
Mark in St. Louis