This is a reproduction of the original 340 4 BBL 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 correct for any Plymouth, Cuda or Challenger with a shaker hood and a 340 4 BBL Set up.  This is the air cleaner base that attaches to the carbs. Lid # NW1004 fits this base.

side to side 20 1/6"

end to end 23 1/8"

hole 4 7/8"

to top of bridge hole 2 3/8"

tall 1 5/8"