The GT40 was a bespoke race car built to settle a grudge. Henry Ford II wanted to beat Enzo Ferrari at his own game after the sale of Ferrari to Ford fell through. Ford failed to beat Ferrari in their early attempts with the GT40 and the entire car went through several revisions to reach the LeMans winning form. These were not typical parts and I would be surprised if they were widely available.
Also, domestic US engine displacements were given in cubic inches. In this case a Ford 7 liter engine is 427 (whole) cubic inches. A period is not prefixed because it is not a fractional measure.