Spark plugs

I run Autolites in my stuff, Autolite Platinums in the stuff that is hard to tune up (like my small block D50) or the stuff that sees very little mileage.

I tried various other plugs in my old D50, back when it had a 2.6L 4-banger. NGK Iridiums (crappiest plug I ever seen, had a 500 mile lifespan), regular NGK's (the factory recommended plug number. had about a 1,500 mile lifespan and gas mileage dropped about 7mpg)

The only plug that ever ran good in that 2.6L was an Autolite Platinum.