hello my question is whats the diference between headers 4 2 1 and a normal headers of datsun 1200 Motor A15

The type where four pipes come together in a single collector are said to provide more power at the fastest engine speeds, but not so much at slower speeds.
The Tri Y [4-2-1] are said to provide more power across a wider range of engine speeds but not so much at full speed. They are supposed to be better for street use.


How about you add some basic location details to your profile so we know what country you are in.