From my observation thru out the F.I. forum, seems like most of stock Vortech runs slightly lean side.(prev 04)
My car runs 12.5-14.0:1 at WOT which is slightly on lean side.
I saw people running even leaner than my set up.
Shouldnt vortech solve this issue when it comes with the kit?

This shouldnt be much of problem if car is street driven but can be dangerous if car was track drivern.

 

That's quite a wide range of numbers. If anything, mine is a bit on the rich side (stock Vortech) with numbers ranging from low 12s to mid 12s at WOT in the upper rev range. Have you checked all your vacuum/pressure lines? The FMU depends on seeing boost pressure to do its thing. Someone here posted a while ago that giving the vacuum/pressure hose to the FMU its own dedicated source can help it to perform better and to lower the a/f number (as well as make it more stable). As is, the kit has the FMU and BOV and MAP box lines "T'd" together. To make it worse, some guys even have a boost gauge on this line. With all these lines coming off the same source, all you need is a weak connection to disturb the amount of boost the FMU sees.

 

Aaaah! I see!!
I have Boost gauge connected to same line!

I should re-route so that FMU gets it's own vacuum line.
But...from where? I see only one vacuume line tho.

 

There are other sources of intake manifold vacuum/pressure. The PCV line is another. If you look at the hoses that stretch between the 2 parts of the manifold, you'll see others.
Keep in mind that many S/C'd owners use "ganged T's" and have no problems. This is but only one possibility. I can also suggest that you install a small zip tie at each vacuum line connection.