Whether you are looking to strengthen your stock 4G63 block w/ upgraded turbokit or go with a stroker kit, Eagle Rods are a must!!! All Eagle "ESP" Connecting Rods are manufactured from a TWO-PIECE FORGING. The forging process forces the grain into the shape of a connecting rod, resulting in a superior fatigue life. The rod cap is forged separately so that the grain runs perpendicular to the load forces, which strengthens the connecting rod. Many aftermarket connecting rods are manufactured from 4340 steel. 4340 specs allow a range of different materials to achieve the desired results. Although it is a more expensive process, all Eagle "ESP" 3-D connecting rods also include higher content of nickel & chrome, which increases the strength & fatigue life without making the connecting rod brittle.