"
And what's this 4.2 blower? It's another, larger-yet version of the 3.6 supercharger architecture for '07-'10 Shelbys, '03-'04 Cobras, and '05-'10
Mustang GTs. Longer by 0.61 inches than the 3.6, the 4.2 is otherwise identical with the latest rotor profiles, water-cooling, and seal pressure equalization. Fans with a serious power streak should look for the 4.2 a bit after the 3.6 hits the market."