277/N11 277 Intake .478″ lift, 236° duration @ .050″ lift.  N11 Exhaust .441″ lift, 229° duration @ .050″ lift.  More intake & exhaust lift and duration than N11/N9. S, S2, 968 cores with welded intake and exhaust. Recommend race valve springs. Peak power near 7500 rpm. Dry sump required.  Price dependent on welding time. Call for estimate.  JME 805-704-8785