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Set of 4 new intake manifold exhaust crossover port plugs to fit 1957-1966 Buick Nailhead intake manifold gaskets.
These can plugs can be used with 364, 400, 401, 425 CID Buick Nailhead engines.
Intake manifold and gasket NOT included.
These plugs will prevent the exhaust ports in your intake manifold from boiling the fuel away in your carburetor which then causes a hard starting condition which is common in all Buick Nailhead engines.
Prevents vapor locking of the fuel.
Keep your carburetor and fuel cool which will give you an additional 18 horsepower and also prevent hard starting.
The nuts used in this kit are the locking style, which will prevent them from ever coming loose.
We also sell the intake manifold gaskets in our eBay store, part number 111-103.