i run the K&N extreem's on my dart. Runs exactly the same ET with or without them so there always on. i clean the tops about 3x more often then the round element. you can defiantly tell it pulls all the air from the top.
68 Dart GTS "HEMI" 10.30 @ 131 pump gas street car 3780# 69 Roadrunner 511 six pack 10.92 drive to track street car