All Magnum engines were tested and rated w/accessories,water pump and alt working.Losses are not the same as the 60's.Bracketry, pumps belts,alt itself are all less drag.Engines were off the line everyday engines once production was started.Yes they may have had a different part or 3 but that was only to test new parts.BTW tested with the exact exh back pressure as the vehicle.

Where do you guys get this misinformation you are posting?