Good header ...I know because its my old jam ..bought it roughly 9 months ago. Looks brandnew makes good topend and on that header comparison ...hit me up on that because we will do it .....every motor is different just like evry header ...no two are the same. Way too many factors to say a header is shit .....doing comparisons on a header should be year long process ....i say this becuz the header should be tested in all types of climate conditions then average the data together and get a average for all headers tested and declare a winner ...based upom there OVERALL PERFORMANCE not just. One time test