The bolt itself is 1" long from tip to the bottom of the flange and is a 3/8" head. It has a non removable (as far as I can tell) metal washer and stem that hold the rubber grommet on it. It is a 1/4" shank with a 1/4"x20 thread.Originally Posted by flynnaz
My son just bought a 1997 Grand Prix GTP. What is the size of the Valve cover bolts? There is one missing on the front cover, and the threads are stripped. I want to use a Helicoil to fix it, but I need to know what size I need. It's a great car otherwise. Thank you for the help
