This is a 1968 only part that is correct for Cougars equipped with the 390 GT "S" code motor. Whether your Cougar has the GT package or not, as long as it has a 4V 390 motor, this is the correct snorkel for your Cougar. The internal dimensions of the opening at the air cleaner base end measure 4 1/8" X 2 3/16", the flange mounting holes measure 5 1/2" on center. The opening for the S tube is 2 3/4". Please keep in mind that our hard to find parts like this are not always competitively priced with what you will find on the open market at swap meets and private party sales. Our primary intent in listing these is for our customers to use this website as a resource to properly identify parts before buying or to identify parts in hand so as to ascertain the correct application. We hope this site is beneficial to all that find it whether you have a Cougar or another like FoMoCo model. Ford part number C8OZ-9A626-B.