I would not use a spark plug that i had never heard of before today, why would you? shruggy work
I use the Autolite # 3934 race plugs in my 15.0 tp 1 compression bracket motor that I race on E85, E85 doesn't like the colder plugs like the 3933 or 3932 shruggy
How much compression and type of fuel and octane are you trying to fire safely work

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)