Two plugs that are correct for OEM spec are:

NGK BP6EFS (or hotter plug BP5EFS)

Denso T20EP-U

Forget all the other choices such as splitfire etc. I purchase the NGK's from ClubPlug.net and get the Denso's from various sellers on Amazon. You will not find either of these plugs at parts stores.

Good Luck,

Jayare