Stage II GT4 / Mods Include: BMC Filters, Aasco Lightweight Flywheel, 82mm Throttle Body, 991 GTS/X51 Power Kit (Intake Manifold, Ported Cylinder Heads & Intake Cams) with Cargraphic Stainless Steel Longtube Manifolds. Dyno run is with stock X51 991 GTS mapping - NO TUNE!