Hi all. Like it says, what should my vacuum be at idle with my mods?

My mods are listed below my sig, it's a link to the post on here somewhere.

Currently, I have a leak with my stock TB. Usual areas, including the BISS screw. Ordered parts. Surprisingly enough, my vacuum has always been between 10-12 at idle. This has not changed with my TB leaking. SHould it be higher than that, like 14-16? My boost is set for 30 psi currently in my tune, and I peg 27-28. Even before my motor was built, i ran the same vacuum pressure of 10-12....

Thanks in advance.