Questions about swapping head unit pulley...

I'm thinking of swapping the head unit pulley down one size. Is the stock pulley size 3.5? If so, the next size smaller would be a 3.25 pulley correct?
Would this be the correct one?
http://www.superchargersonline.com/p...r=PAX2H038-325

I also need to know if I need any special tools to do this and if so what tools.

BTW...I already have the 8" lower so should I go to a 3.00 or would I be maxing out the blower already with the 3.25?
I'm pushing ~10-11lbs now and looking for a solid 12lbs.

Thanks

I didnt think you could go to a 3" could you? Lowest I seen was 3.25". Im looking to do the same thing, although not anytime too soon, I want to see what answers you come up with.