Rocker Arm - 1.60 Ratio .375 Offset Left

The Rocker Arm - 1.60 Ratio .375 Offset Left by T and D Machine is a precision-engineered valve train component designed for serious engine builders and high-performance enthusiasts who demand reliable, consistent lift profiles. This left-hand rocker arm is engineered to optimize valve actuation geometry in custom and modified engine builds, particularly in applications requiring specific mechanical advantage ratios and stud-mounted configurations. Whether you're building a stroker, upgrading cylinder head performance, or fine-tuning a competition engine, selecting the correct rocker arm ratio is fundamental to achieving your target horsepower, fuel efficiency, and valve timing objectives.

The 1.60 rocker ratio multiplies camshaft lift by 1.6 times, increasing valve opening distance compared to a 1:1 ratio and improving volumetric efficiency at higher RPMs. The .375-inch stud offset positions the rocker fulcrum point precisely for optimal geometry with aftermarket and OEM performance camshafts, minimizing valve lash variation and reducing stress concentrations during extreme valve events. T and D Machine manufactures these rocker arms from hardened steel with precision machining tolerances, ensuring dimensional accuracy across thousands of cycles and extended engine operation. The left-hand designation indicates this arm controls the driver-side intake or exhaust valve, requiring matching right-hand arms for complete cylinder head conversion.

This rocker arm suits small-block and mid-block applications where stud-mounted arms and 1.60 leverage are OEM or popular upgrade specifications. Engine builders specializing in classic muscle cars, street performance builds, and circle track racing frequently specify this ratio for balanced low-end torque and mid-range power delivery. Installation requires proper pushrods, adjusted valve lash, and verification of geometry clearance; mismatched ratios or stud hole diameters will result in poor fit and valve train instability. Always purchase complete rocker arm sets in matching ratios to ensure symmetrical valve timing across all cylinders and consistent engine operation.