All -

I am planning on getting a 6 rib 5.75" crank pulley from Buldogge to augment my current Dinan Powerdyne system. I am currently running 5.5 psi and am shooting for somewhere between 8 and 9 psi. I have two questions:

1. What size belt would I need to get?

2. Looking at my latest dyno, would it be safe to do this boost bump without new software? The car is running pretty rich up top, dyno (red graph is the latest):
http://members.cox.net/vshah/m3_dyno_new.jpg

Thanks.