[DIYguy]

Z0Tex has told me that the original version of the 30mm plugs are too big to fit a V8 intake pipe orifice.
30mm is the correct size for V6 intakes though.
I will re-design them once I receive measurements and then post the corrected versions.
I found an older thread that mentioned 15/16" (23.8mm) as possibly being the proper size but that needs confirmation.

Thanks very much for testing them Sean, I appreciate it.