i had a puller at my work. it is similar to the one on south florida pulleys website. they sell the tool as well!! it's actually a pretty easy swap. my stock guage gets buried past the 10lb mark. i need to get an aftermarket guage for it! most of the guys i've talked to are getting 12-12.5lbs total boost. If your worried just get one of the bigger pullies for the street and then when you go to the track you could put a smaller one on! the cool thing is that pullies are easily swapable with there system!check out this site:
svtperformance.com
lots of good info on our cars there
my buddy has a 03 cobra and i took him for a ride in mine! he is ordering some pullies for his this week!! he was very impressed
good luck.
Leon