73 340 duster thermoquad spacer ?

-
Spacer, no. But the correct gasket is already over 1/4 inch thick...
1726756345527.png
 
Some possibilities for the thick gasket:

- Base gasket (open): Chrysler 3879786, Fel-Pro 1902, 60273, McCord 66-0144, Victor-Reinz G14589 (G26662 for 1971-1972), Rol CM55011 (CM55256 for 1971-1972), Walker G897, Mahle/Clevite G14589.
 
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.
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?
 
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?
No thin paper gasket. Just the thick insulator gasket.

Thremoquad gasket. There is also an open hole version of the Thermoquad gasket, but as you can see, the Thermoquad gasket has a thicker back wall. Using the Queerdrajet gasket on the Thermoquad will result in a vacuum leak around the back of the secondaries. Most stores will try to sell you the wrong gasket, because they want to stock as few parts as possible.
THERMOQUAD GASKET.jpeg


Queerdrajet Gasket.
QUEERDRAJET GASKET.jpg
 
No thin paper gasket. Just the thick insulator gasket.

Thremoquad gasket. There is also an open hole version of the Thermoquad gasket, but as you can see, the Thermoquad gasket has a thicker back wall. Using the Queerdrajet gasket on the Thermoquad will result in a vacuum leak around the back of the secondaries. Most stores will try to sell you the wrong gasket, because they want to stock as few parts as possible.
View attachment 1716305455

Queerdrajet Gasket.
View attachment 1716305457
Thanks for the illustration Rob. I figured something was going on. I always thought there was a thin gasket above and below since the original aluminum spacer had a gasket above and below.
 
Thanks for the illustration Rob. I figured something was going on. I always thought there was a thin gasket above and below since the original aluminum spacer had a gasket above and below.
What "original" aluminum spacer was that?
 
Got a picture? I've never seen one. What was the purpose?
I bought a repro. I think Mopar was just figuring things out. I'll see if I can find it. I vaguely remember it being correct. Two thin gaskets and a thin aluminum spacer in between. I had a "71" 340 four speed Duster for a while.
 
Cool. I would like to see that. I wasn't aware the factory ever uses a spacer. What was its purpose?
Only guessing, space it up for correct choke operation or an attempt to insulate carb from intake heat? I remember pitching the cluge and just running the thick gasket. I did a lot of stupid stuff back then.
 
Only guessing, space it up for correct choke operation or an attempt to insulate carb from intake heat? I remember pitching the cluge and just running the thick gasket. I did a lot of stupid stuff back then.
The only reason I was thinking was maybe if they used some left over 70 intakes on the early 71 and used an adapter plate for the TQ. Evidently, that was not it.
 
No, it was the good, ...100 casting number, I still have it and the TQ. That combo was too good to let go.
Yeah. My understanding is the 71 TQ was the best for all out power, but they kinda had trouble on the street. But I've never had one or worked on one.
 
Only guessing, space it up for correct choke operation or an attempt to insulate carb from intake heat? I remember pitching the cluge and just running the thick gasket. I did a lot of stupid stuff back then.
The gaskets above and below the spacer are quite substantial, Almost like something you'd see on a fibrous exhaust manifold gasket with metal impregnated.

Probably asbestos so that's why I opted to stay away from scraping it clean to re-use.
 
-
Back
Top