The connecting rod is the vital link between the piston and power. When engine output is increased, the demands placed on the connecting rod increase as well. To ensure engine reliability in all conditions, original connecting rods should be replaced with heavy duty specification parts. Cosworth Forged Connecting Rods are manufactured from high strength 4340 (EN24) steel and machined to exacting tolerances. Sold in a matched set of 6 rods.