Spark Plugs?

[Fastand fury]

I have a 64 Sport Fury, 383 block but is now a 496 stroker! I'm running a Edelbrock Performer, a 770 Holley and electronic ignition. Trying to find the best spark plug to use.

 

[pnora]

What heads?

 

[Geoff 2]

NGK '4' heat range if alum heads, '5' if cast iron.

 

[not so famous bob]

NGK '4' heat range if alum heads, '5' if cast iron.

I`ve got 5`s in my 440/505 , been thinking about going to 4`s , what size engine are you running them in ??