Be it a Hemi Dart or Barracuda, an A12 package car with its "Six Pack"-style scoop, or a T/A Challenger with its T/A-style scoop, they all had one purpose-getting fresh air to the engine.

Here are the aftermarket air filters we tested in this '04 1/2 Dodge Ram 2500 equipped with a manual transmission. Clockwise from the top left are: K&N, Volant, AFE, Airaid, True Flow, and S&B.

Ram-Air was standard on '71 429-R and Boss 351 Mustangs and optional on 351 models in 1971-'72. Interestingly, at mid-year '72 and throughout '73, it was available only with the 351C two-barrel ...