These plugs allow you to remove the exhaust air supply rails from heads with the Thermactor Emissions System.

Our plugs fit flush and will clear aftermarket headers, unlike the Ford plugs which are now obsolete.

Eight are required for V8's and fit 289, 302, 352, 390, 428 engines.

They are also available in packages of six for 6 cylinder engines.



Mustangs, Etc.