Hot Rods flathead spark plugs

8BA, .425 Offenhauser heads, Red's Headers, Mallory electronic, E-coil. 390 Holley, Isky Max1.

What is the best plug for this application?

Thanks!!

 

from the old days we used Champion H-10

 

How to light a thread.....#1 Autolite 437 for aluminum heads (power tip),
#2 Autolite 216, #3 Champion 271H10.
Now wait and get four or five different answers......

 

Ngk b6l

 

autolite 216

 

I run the NGKs with nearly the same engine that you have. I like em.

 

autolite 216 they bite better into aluminum heads,thats what I run and problem free

 

Measure the thickness of the heads and pick a plug that has the right reach for the lift of your cam.

 

I run NGK B6HS plugs in my 8BA, gapped at .040, they have the correct reach. It has Offy 425 heads, .320 lift cam that is custom ground, very similar to an Isky88. MSD Ignition.
Bill

 

NGK R5672A-(X), X being the heat. I found this article which explains it all:

http://www.ngkplugpro.ca/content/co...mendedSparkPlugsforEdelbrockCylinderHeads.pdf