my car: 65 Riv GS with stock 425 Carter dual quads and stock intake manifold. What was under the carbs: fibrous gasket on bottom, SS heat shield in middle, thin fibrous / paper gasket on top. What gasket vendor says: no need for the SS heat shield. just a standard gasket as there is no true open heat path from block to carb. erfectly willingbto sell me two, but insists it does not truly belong. So -- completely unnecessary? Necessary? not necessary but still a good idea? Please advise.
That's it right there. There is a carb heat channel cut into the surface but it's not drilled to the actual exhaust like the 1x4 manifolds are.
With todays crap pump fuel that boils at 140 F I myself would still install a modern insulated gasket under each carb!
The Buick parts book calls for the stainless gasket even in dual quad application even though there is no direct exposure of exhaust gases to carb base. Besides preventing direct contact of exhaust gases to the carb, the stainless plate was also present to distribute warmth around all 4 barrels of the carb to prevent icing...that was back in the day.... is that really a concern for a fair weather collector car? Most folks with collector cars now are concerned more with heat soak than carb icing because the type of use is more narrowly focused not to mention the change in what is typically called gasoline. Your call ! Tom Mooney
FYI the 1/4 inch spacer listed above will not fit a stock Nailhead manifold. I you look close the gaskets have 2 sets of holes and the spacer only one. I am looking for correct spacer but so far unale to find.
