I've got a set of Clifford headers on my 4banger, and, aside from price, I like'm! I feel they improve the low end torque, which on a trail Jeep in my situation is what counts the most. I still have good power and torque thruout the rpm range for the times I need to find out if the rev limiter works. The other mods on my banger include a Clifford cam and lifter set (pricey!), homemade throttlebody spacer, and work in the intake manifold to eliminate restrictions and sharp edges. I have a temporary "cold air" intake that will be replaced later on with a home made cowl intake. The short tube headers make good power higher up in the rpm range. That is useful to some folks and for the manufacturer gives them a better HP figure to advertise. Low and midrange torque is more important to daily driving and trail riding than top end HP. Somebody said that "Horsepower determines how fast you hit the wall; Torque determines how much of the wall you take with you..." In my mind, Torque figures mean more than HP.