Trying to help get info on what plug to use with a set of 440 source big block heads. What do you run? What is the part number for Champion and Autolite? Thanks for the help in advance!
For my 10:1 compression street car with Stealth Heads, these seen to work good:
NGK #2756 plugs (Plug Part # BKR6E-11) which is a 6 Heat range.
The Plug part # breaks down as:
BK = 14mm thread, 5/8" Hex ISO Type (shorter ceramic part)
R = Resistor Plug.
6 = Heat Range.
E = 3/4" Thread Reach.
-11 = Spark Plug Gap of 0.044"
The #2 plug is pretty close to the inner fender on my Coronet, so I also use the special Snap-On spark plug tool:
https://store.snapon.com/Hand-Sockets-So...ex-P644223.aspx