3.3 with a 6lb lower on a stock block will be perfect. Probably right at 15lbs and should make 450 rwhp.
KB makes a 3.5 and even a 4.0 I think. But if you want something different than check out these then. The numbers in my sig. are on stock block with a 5# lower and 3.2 upper on pump gas. When we did the tune on the 3.5 it was 20hp less.
http://www.southfloridapulleyhq.com/SFPH/lightning/ps_ts_nonslip_pulley_system.htm
I'm trying to stay under 450rhwp. I'd like to keep my stock block together as long as possible. If I went with a 3.3 or a 3.2, I'd probably switch to a 4lb lower.
When I sent the KB in for a rebuild, I asked KB to install a 3.5" pulley on it before sending it back. They didn't. I'd rather spend my money elsewhere rather than giving them even more money for poor service.
I saw SFPHQ's website earlier when I was looking, but I've never done business with them. I didn't find many reviews on the net either. Have you purchased from them before?