If you need plug replacement on a low power flathead - what are you doing wrong?
Uless you are a lawn care guy using it multiple times a week for hours.
A Hmeowner you would typically never put enough hours to need to change a plug on home
And you don't mess with good running ignition if i doesn't really require maintenance
Autolite makes excellent Ir plugs. Good for Subaru service replacement.
Take note Subaru guys with FB powerplants - forget thefactory Ruthenium - you don't need them.
( most Ir is a Ir-Ru alloy anyhow)
I hate NGK. Built up this distaste with a passion over decades of professional tuning and repair.
Their Ir design from two decades ago saved NGK.
NGK USA V power is junk. BK or BP 5 or 6 R ES-11 Japanese O.E. are short-life and low quality. Good for their
My weekly NGK rant - over for now