The WCFab 2001-2016 Duramax Up Pipe Bolt Kit is comprised of 6 specially selected high strength 12 point ARP fasteners and matched washers with a pack of assembly lube and are designed as an upgrade to the OEM fasteners employed on the 2001-2016 and newer 6.6L Duramax engines to connect the up pipes to the exhaust manifolds and turbocharger pedestal. During our performance development work on these engines we have seen numerous occurrences of factory fasteners seizing or breaking in the manifolds or pedestal.. This kit is a simple, cost effective upgrade for peace of mind and ease of serviceability for both stock and modified trucks.