Ok here's the scoop. Because a VNT is a more complex setup, you have three main solenoids to be concerned with - your Barometric, and the 2 VNT solenoids.
If you look at your VNT vacuum diagram under the hood, the barometer solenoid is at the top (furthest from the front of the car). For the sake of reference, I'm going to call this Sol1. The next one down, right below it, (on the left if you're standing on the passenger side of the car facing into the engine bay) I'll call Sol2. Then there's a void space, and next to that there are 2 more solenoids. The one next to the void space I'll cal Sol3 (Sol2 and Sol3 are the VNT solenoids, the other, closest to the front of the vehicle, is the Purge Solenoid, which we won't be touching. The VNT solenoids are on either side of the void space)
Confused yet? I'll throw in a diagram, because words just don't do justice. I should point out that I've changed my vacuum lines in this picture, so it's not quite how it looks stock, but all you need to know is that they still work the same as your lines.
The only line you will be modifying is Sol3. However, I highly recommend getting new vacuum lines for Sol1 and Sol2, and checking all your vacuum sources to ensure there are no leaks (especially if you're bone stock - the old lines are garbage). I used some 5/32 PCV line, as well as some 3/8 and 5/8 PCV line for the larger lines (some 1/4 is also useful).
First off, you need to cut the line going from the top nipple of the wastegate can to the middle nipple on Sol3. I recommend doing it closer to the solenoid to make it easier to work with. Reconnect it using a vacuum T, and some 5/32 PCV hose. I'd tie wrap (zap strap) these hoses where they connect to the old ones if you don't replace the lines because they will blow off with the extra boost.
Second, you need to cut the line going from the turbo outlet nipple to the top nipple on Sol3 (again, I'd recommend closer to the solenoid). Add in a restrictor (more restriction/smaller hole = larger spike) on this line, make sure it won't leak vacuum, tie wrap it if you use the stock hoses, and you're set.
Finally, get an Air/Fuel Ratio gauge. More boost needs more fuel. The mantra of all Turbododge owners holds true here.
Hope this is helpful - Click the pictures for a full sized image of them - the thumbnails are just space savers.
Jason
TurboDodge.com 
