Have you been considering building your E8X / E9X but weren't sure where to start? Unsure of what components to pair for the best possible power and reliability combination? We receive inquiries daily from N54 owners interested in building their engine but unsure where to start. The 5150 AutoSport Complete Engine Build Kit features every component you need to fortify your BMW N54 internally and prepare your engine for high power, high boost applications. These components are the combination that we have had the most success with and recommend as a result. Please note that each engine kit requires a consultation before shipping, and one of our engine build advisors will contact you regarding your piston configuration, compression ratio, etc. before shipment. This kit includes: High Performance Valve Spring Kit High Performance Intake Valves High Performance Exhaust Valves High Performance Valve Locks CAT Cams 274°/270° Camshaft Kit ARP High Boost Head Stud Kit** **it is a MUST to drill and tap the four outer 9mm holes in the engine block to increase their size to 11mm holes Athena-SCE Cut Ring Head Gasket CP-Carrillo Forged Pistons HD Wrist Pins CP-Carrillo or SP Components Forged Connecting Rods Calico Coated 5150 AutoSport High Performance Rod Bearings Calico Coated 5150 AutoSport High Performance Main Bearings