Mine fit fine on my '68 under the Power By Ford valve covers when I changed from studs to bolts. The studs won't clear.
http://www.villagephotos.com/image.asp?id_=18953757
1912 Model T Ford touring Salmon (ugh!)
1913 Model T Ford Touring original Black paint
1915 Model T Ford Roadster Black
1915 Model T Ford touring Black of course!
1967 Cougar GT 390 Cardinal Red / Black
1968 Cougar GTE 427 Augusta Green / Saddle
http://www.supermotors.net/vehicles/registry/15029/50071-2