This is a reproduction of the original 426 hemi air cleaner base plate.  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 the air cleaner base that attaches to the carbs. Lid # NW1002 fits this base.

side to side 20"

end to end 21 1/2"

carb inlet 4 1/8"

center hole to center hole 6 3/4"

depth 3 1/4"