Which is better the gen 3 duratec or gen 4 motor. I know they basically have the same ratings. From what I've read, the gen 4 seems to be the more powerful of the 2 motors. As I understand it, the gen 4 heads have large oval ports, and no secondaries. Where as the gen 3 heads have small primaries and medium sized secondaries, that open up at 3000 rpm (according to haynes manual). This would lead me to believe the gen 3 would have far more low end torque, and less high end horsepower. However, from the way everybody is talking about the gen 4's, they don't seem to be lacking in low end torque. Are they geared lower by any chance. Is there a piece of the puzzle that I'm not aware of. I just figured the low end torque would beat out the high end horsepower of a hefty taurus with stock differential gears in a race from a dead stop. Sure the high end horspower of the gen 4 would be better on the oval, no doubt.