Ford Flathead 8 Chrome Head & Intake Bolt Cover Kit (70 pcs). Here is a your chance to spiffy up your flathead 8 engine. Nice and easy project. There are 50 head bolt covers (11/16" ID) and 20 intake bolt covers (9/16"). The head bolt covers are 11/16" ID and the intake covers are 9/16 ID measured across the flat. They are metal.