From what I've been reading, a lot of guys have been doing it. Looks like there's 3 pully's available. 2.3, 2.4, and 2.5.
I'm thinking about doing it, but I worry about the blower bearings. I've been looking into the cost of new bearings, before I do this, and I've seen prices ranging from $150 up to $1000, so I havn't nailed that down, yet.
One thing I've noticed is that with a free flowing exhaust, you acually loose boost, so I'm thinking a 2.5 would bring the boost back to factory.
A 2.4 will give it a little more and a 2.3 will up the boost to around 10-12 psi. I think the 2.3 causes the blower to exceed max rpm under wot, but nobody's reporting any problems. But you know how that goes.
When I do it I think I'm going to go w/the quick change type. Off the top of my head I think that's about $150 w/1 pully. $70 for ea. add. pully. $40 to rent the pully tool or $130 to buy it.
Right now I'm messing w/the air intake. I've got a K&N drop in and I pulled the fender resonator this afternoon. Pulling that res. gave me a little snappier throttle response, but little more.
Have you checked out pulleyboys.com?