Manifold sealant

[Morris R.]

What was used on a 66 corvette 327/350hp intake manifold between the cylinder head for a sealant? A gasket or silicone, and if it was a silicone what would be recomended? Thank you

[Joe L.]

Re: Manifold sealant

What was used on a 66 corvette 327/350hp intake manifold between the cylinder head for a sealant? A gasket or silicone, and if it was a silicone what would be recomended? Thank you

Morris------

Silicone was never used for side gaskets (i.e. the ones you're referring to). The side gaskets for all 1966 applications were an embossed type gasket with a steel core. This type gasket is still available today but harder to find. An easy way to obtain them is to use the reproduction gaskets as reproduced by Paragon.

By the way, the end seals for the manifold installation were originally rubber for all 1966 applications. These are supplied with the above-referenced reproductions as well as most other aftermarket gasket sets. However, I recommend the use of silicone RTV for the end seals.

[Ray G.]

Re: Manifold sealant

What Joe said and;
Allow me to add, if machine work was done to the heads or block from original stock castings, the clearance between the intake manifold and engine block will be reduced forcing the rubber end gaskets to be pinched and sometime cut by the pressure. Additionally if the Corvette is to be judged the Judges look for the rubber end gasket tabs.
my .02