This is a reproduction of the original 426 hemi shaker base air cleaner.  The base is made out of metal just like the originals.  Don't buy the aftermarket fiberglass ones to save a buck, they don't work!  This is the stock size for the AFB carbs, if you want a base for bigger Edelbrocks we carry those as well.

This is correct for any Plymouth Cuda or Challenger with a shaker hood and a 426 hemi.  This is the air cleaner base that attaches to the carbs.  It is about 6 3/4 inches between the carb stud holes. Lid #NW1002 fits this base.

side to side 20"

end to end 23 1/8"

carb intake holes 4 7/8"

center hole to center hole 6 3/4"

tall 2 1/2"