Back in 2011 I had my carburetor rebuilt by a shop which I used by the time, and before I did all the work by myself. When I got the car back from the shop, I suddenly heard a loud ticking noise (like an exhaust leak) which came from the side of the carburetor and the car idled terribly. As I soon found out the shop had the gasket and the metallic spacer installed in the wrong order, and because of this the gasket burned through, which caused a massive leak at the carburetor.
A new gasket was installed in the correct order then and the car ran really good until recently when the car suddenly had the exact same symptoms again…
I ordered new gaskets again and removed the carburetor from the car.
I then found the reason for the reoccurring problem. The shop had installed an incorrect gasket on the base of the carburetor which does not belong there. It is included in the rebuild kit for this Quadrajet though, but there are a few parts included in the kit, which should not be used on this application. This wrong gasket covers a hole to the carburetor which should be open, so that the heat from the manifold can warm the carburetor. This wrong gasket blocked this circulation and caused blow by on the gasket.

I'm shocked that a specialised shop would install this incorrect gasket at all. I had many of this kind of problems with this shop, and thats why I started to do all the repairs on my own or with the help of my competent friends.

I removed the incorrect gasket and reinstalled the new correct gasket and the metal shim , cleaned the Quadrajet and reinstalled it. I then torqued everything to specs (see excerpt from shop manual below) and everything works again as it should.

The ticking noise came from the right side of the carburetor.
The new gasket and the cleaned metal shim.
The gasket blew at the heat crossover passage.

The correct torque specifications for the Rochester Carburetor.
Gasket has to go first - then the metal shim!

Gasket first - then the metal shim. No more base gasket on the underside of the carburetor!!7027235 is the number of the 67 Eldorados Quadrajet

This shows the wrong black gasket which was installed underneath my carburetor. As you can see it is blocking a hole ad does not fit on the sides. It is included in the rebuild kit, but it is not installed on this application!

Tags:1967, Cadillac, Rochester, Quadrajet, Gasket, 7027235, 1967 Cadillac Eldorado Repair Tip