LS PISTON PIN SIZE
Stock GM LS full floating connecting rods use a .943″ pin and stock LS press rods use a .945″ pin. Some aftermarket forged pistons designed to use a stock LS 6.098″ length rods come with the .945″ pin type. Pistons can be used as “Pressed” or “Floating” and are supplied with lock ring grooves and locks for .943″ rods that must be honed for floating pin clearance. This way one piston can be used for either connecting rod type. Many, if not most aftermarket forged LS pistons come with a .927″ small pin, like those used in small block Chevy’s. They also have a shorter compression height to accommodate an aftermarket 6.125″ long connecting rod. Care must be used when shopping aftermarket pistons to match the correct connecting rod pin size and length.

Engine Pro Tech Committee and special thanks to United Engine and Machine / Icon

April, 2024