You're gonna love it...but...did you tell them to give you a 14mm plug-hole adapter instead of their usual 18mm? Aircraft engines use 18mm spark plugs, like some old Chryslers and Fords. Most automotive spark plugs are 14mm, although a lot are even smaller--like motorcycles, they've gone to 12mm and 10mm spark plugs.
All those adapters are available, but there's an extra cost. Once upon a time, I took an old motorcycle spark plug (12mm) broke the porcelain out of it, and then threaded the shell for 1/4 pipe thread so I could screw a compressed-air coupler plug into it. Made my own motorcycle adapter. Should have started with a Champion spark plug, they have the most-brittle porcelains in the industry when I quit buying them thirty-something years ago. As is, the ND or NGK plug I was breaking the porcelain out-of fought me all the way.
The "Master Orifice" allows too much leakage for performance automotive use. I look at what the Master Orifice allows, then cut that by a third or half and use the smaller amount as my limit. Someday I'll make a smaller, more-restrictive Master Orifice, but it's not high on my list of priorities.
