73 340 duster thermoquad spacer ?

RustyRatRod said

Correct, BUT, make DANG SURE you get the correct gasket. A Quardajet gasket is NOT the same. They will cause a vacuum leak around the back of the secondaries.

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Hmmm.....I think I got that. Engine runs good (idles with 11 A/F ratio) but has a large sucking sound that seems to be coming from the rear of my TQ. I spayed some water in the center area of the rear base and noticed a definite change in the idle. How would one recognize the difference between the 2 gaskets?

Also, is there a paper gasket installed above and below the thick one?