yeah smaller pulley spins the supercharger faster, boosts quicker (noticed a big difference with the 62mm TB installed as well, hits peak boost even quicker) in turn causing it to scream louder
www.glowshiftdirect.com for gauges
www.pfyc.com for the 2 or 3 pillar gauge pod
www.smoothflowpulleys.com just e-mail Nathan for an MP45 modular hub and he'll make one for like $50 shipped