The purpose of the engine main bearing girdle is to increases block rigidity and tensional stiffness; it does this by tying all the main bearing caps and oil pan rail together. Our GORILLA GIRDLES are designed using the latest CAD software and machined using a CNC milling machine and lathe. Engines that use a main bearing girdle make more power, by decreasing friction in the main bearing bore and overall alignment of the piston and crankshaft bores. The main bearing girdle will strengthen and stabilize the bottom end of the cylinder block, evenly distributing the load across the main bearing caps, virtually eliminating main cap walk. This 14mm girdle is being used on engines producing well over 1500 H.P. The 14mm kit includes the girdle and all hardware needed for installation on the Cummins 12 – 24 valve 5.9 diesel engines. This kit requires the use of our 14mm extra long stud kit.