98 Cobra with T-trim - what pulley???

K my setup

- 98 cobra block - stock (i know i should have a forged block)
- aviator fuel pump
- 42lb injectors
- 90mm maf
- cat back magnaflow
- custom\paxton intercooler (don't know yet)
- Vortech T-Trim using 6 rib pulley
- KB Boost a spark
- Methanol injection
- custom tune chip

I wanna run 10-12lbs of boost...any idea what pulley size? I have a 3.25" which I think will give me 14-15lbs, which is way too much for a stock block. I'm more concerned with reliability. Looking for roughly 450hp