This 6-rib 2.49" pulley is a very popular upgrade for owners of new Mustangs equipped with Roush M-90 Superchargers who wish to add more boost. This is a press on pulley like is found on most 09-10 Roush Mustangs with a M90. Easy way to add another 3 to 4 psi of boost over stock.
The pulley is CNC-machined from high-grade steel for precision fit and extreme durability, and the surface is black oxide-coated to prevent rust. The pulley is keyed and installs as a direct replacement for the original Roush supercharger pulley.
It is recommended to replace the factory idler pulley located directly beneath the supercharger pulley with a Metco Motorsports billet idler pulley, PN MIP-90 .