1974 Carb Base Gasket-Which One?
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
1974 Carb Base Gasket-Which One?
My Q-Jet was misbehaving so I decided to correct the situation by purchasing a re-manufactured unit from NAPA rather than rebuild the old. They came across with a #7044202 (1974 Chevelle automatic) to replace the original #7044206 (1974 Corvette automatic). Very close and all the ports, emissions spouts, brackets, etc. were in the right place! I was impressed.
In any case, the pic shows the old carb. The base gasket on the left was on the car. The one on the right came with the new carb. They are obviously different in the area of the idle mixture screws and PCV inlet: one gasket covers that area and the other does not. Which gasket is correct?
In any case, the pic shows the old carb. The base gasket on the left was on the car. The one on the right came with the new carb. They are obviously different in the area of the idle mixture screws and PCV inlet: one gasket covers that area and the other does not. Which gasket is correct?
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
I saw his comments on the "hot-slot" issue for early C3 intakes but that is not relevant in this instance as there is no slot in 1974.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Either one will work just as well. It doesn't affect the mixture screws or the pcv.
If you have heat problems in your neck of the woods, you can also add this stainless heat shield and another thin base gasket. I always do, but it is always very hot here.
If you have heat problems in your neck of the woods, you can also add this stainless heat shield and another thin base gasket. I always do, but it is always very hot here.
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Lars provided these comments off-line. I thank him.
The correct gasket is the one on the right. However, it does not make a difference which one you use, since the plenum areas in that forward part of the carb are all interconnected through the large open area in the throttle plate - all the passages are connected to manifold vacuum regardless of the gasket you use. But I use the type on the right, and that's what was used by GM.
The correct gasket is the one on the right. However, it does not make a difference which one you use, since the plenum areas in that forward part of the carb are all interconnected through the large open area in the throttle plate - all the passages are connected to manifold vacuum regardless of the gasket you use. But I use the type on the right, and that's what was used by GM.
