With the Eaton and Autorotor chargers we've had difficulty getting much more than 120-150 degrees of belt wrap, and with only that, you'll be facing slippage. If you have any notions about eventually going more than 5-10 psi on the boost, you might want to consider an 8 rib.
Even with an 8 rib I was experiencing slippage at 18-20 psi on my Opcon Autorotor 322. I'm now changing to a dedicated Gilmer type drive.