This is a brand new rubber valve cover plug for original 401 & 425 cubic inch Buick Nailhead valve covers. 
This plug is correct for stock stamped steel and optional finned aluminum valve covers. 
**Please read entire item description.** .

This valve cover plug will fit the 1964, 1965, & 1966 valve covers for the 401 & 425 cubic inch Nailhead engine. 
This plug does NOT fit the pcv hole NOR the twist in breather hole. 

For the stock stamped steel valve covers this is the correct plug for the hole in the driver front corner.

If you have finned aluminum valve covers please read the following:
This valve cover plug fits the other large hole in the 64/65 California version, as well as the 50 state 1966 version (the 1966 version has the indentation in the front corner).
The 64/65 49 state version does not have the large extra hole in them so this plug is NOT needed. 
If you have questions questions on fitment please ask or send me a picture of your valve covers and I can confirm fitment.

***This plug DOES NOT fit the following aftermarket valve covers: Offenhauser, PML, Fenton, Kring, nor any other aftermarket valve covers for the Nailhead engines.***

Please ask questions.

64 65 66 1964 1965 1966

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We specialize in Buick parts!

The Buick models that we specialize in are below:

1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, and 1970 LeSabre, Invicta, Wildcat, and Electra 225 models 

1963, 1964, 1965, 1966, 1967, 1968, 1969, and 1970 Riviera models

1961, 1962, 1963, 1964, 1965, 1966, and 1967 Special, Skylark, GS, Sportwagon models

We specialize in the following Buick engine parts:

Nailhead: 264, 322, 364, 401, 425

V6: 198, 225

V8: 215, 300, 340, 350

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