Hi, Why did some of these air cleaners get the vacuum trap doors and others didn't. Thanks in advance T

I was under the impression that the trap door was a 72 thing and 73 did not have it.I know my 73 cuda did not have it.

That was my understanding too. Maybe some early 73's recieved left over 72 air cleaners....or vice versa.

Here's a pic of mine from 2007 just before I sold the car ('73 Charger Rallye 340). This should be the original air cleaner - I don't remember if it had the flapper or not, but it does have the vacuum pod:

Need to find some untouched survivor cars.

have the air cleaner for my 73 340 duster in the shed will have to take a look at it..but i think it does not have the air valve.

I have an air cleaner with the door off a '73 340 rallye. My '74 rallye 440 also has the door. Not many '74 440s out there and all I have seen had the 1 long, 1 short dual snorkles.

The 73 parts book lists two 340 part numbers, before and after Dec/72. The before number is also in the 72 book. Perhaps there were new emission rules for Jan/73.

They always used up old stock befor changing to a new part.

My January build 73 Charger Rallye 340CID has its original air filter housing. It does not have that flapper. My understanding is that 72 340s had them. Could they have removed them as a cost saving or some noise regulation?

I'll have to check my '72 Cuda 340. Haven't had the hood up in years as it awaits it's restoration. It is a survivor car.

1973 Cuda 340 built Oct 72 has the vac flap on the passenger side. I currently have and use that one in the winter