Ive seen weights all over the place, the Gen III's are lighter than a all iron small block for sure. On another site a fellow weighed his truck Eagle 5.7 at 512 lbs. with no accesories and no fluids. Another fellow weighed his low deck 470 that was all aluminum but block and it came in at 519 lbs with 7 qts. of oil. Im not going to a Gen III for weight savings. They just flat run and are efficient pumps.