Where to tap into for my AutoMeter boost gauge???

I'm trying to hook up my AutoMeter Boost Guage for my '01 GTP. Where would i tap into for the sensors??? I had just replaced the pulley to a smaller 3.4" one. Any suggestions???

Install off the MAP sensor vacuum line. See link below:

http://www.grandprix.net/upgrades/boostgauge.html