Originally Posted by cupcakez

Thanks guys!
Sounds like I will purchase the ones from Z1 from the link I put up in the OP.

Although, it would still be interesting to find out the difference between SpecialtyZ spark plugs [vs] Z1 motorsports as the size difference is about .10mm apart, haha.
Looks like one is made in Japan the other is not, as I do not see the word "Japan" on the other one xD