Precision Dense Chevrolet 265-400 Connecting Rods We use superior ASTM 4260 blend. We used CAD solids modeling for proof of concept and machined models from billet. We use Finite Element Analysis, a computer program that accurately simulates stress and reaction to stress, which allows redesigns for better strength and weight reduction in the correct places. This greatly reduces the design cycle time and accurately predicts strength and fatigue resistance before the rod is manufactured and sold to you