What is the difference between a 4-into-1 header and a 4-2-1 header?
In many cases 4-into-1 headers are designed for racing applications where the vehicle is being driven at or near redline during competition. The 4-into-1 design maximizes top end power, whereas the 4-2-1 evenly distributes power throughout the power band. There are cases where a 4-into-1 header works better than the 4-2-1, and in those cases we will only manufacture a 4-into-1 design.
