ok now more specifics on how the third valve cover is mounted-first, the valve cover is 3 &1/16" wide all the way down. This gets the cover to rest on top of the tapered edge of the factory NA valve covers, but it will not fall through(basically the NA valve covers are holding the 3rd valve cover up). Then, in the spark plug valley there are three 14mm plugs-the one closest the the #6 spark plug is tapped for a bolt mesuring 8x1.25mm.(This is where the factory throttle linkage is held in with a bolt.) I got another plug like that, and replaced the front plug. Now you have 2 mounting points to hold the cover in place-just drill the holes to match the plugs, and install bolts to secure. I believe the bolts I used were 60mm long. Let me know if you guys have any more questions-I know it seems confusing.