I'm going to be using the FL-400S on my sister's ZX2 (obviously not a 4.2 V6, but it uses the same size filter). It seems to be the best bang for the buck. I have one Purolator Classic as well, that I got as part of one of their oil change specials. The Motorcraft has a different bypass setup and a silicone ADBV rather than the nitrile that comes with the Purolator Classic. The kicker is that the Classic actually costs more!