MIKE S. - The ONLY thing that effects the stroke is the offset of the crankshaft throw from the centerline of the crankshaft. Connecting rod length and wrist pin placement effects the placement of the piston in the bore but doesn't effect the stroke. There's torque to be gained in engines by using longer that stock rods with high wrist pin pistons because of the angularity of the rod, wrist pin, and crank throw which parks the piston at the top of the bore longer and allows cylinder pressure to soar but that is typically only noticable in hi-performance automotive engines.