My home inspection of Speedmaster heads

I think the Trick Flow is not much different then any of the SM head in the as cast condition.
EDIT see at bottom



Just think that it might have been a better plan to have NOT tapped the spark plug hole all the way threw.
In any case, i would be after the sharp edges on the combustion chamber.
This is a Trick Flow Spark plug design.
Sorry for the confusion!
VVVVVVVVVVVVVVVVVVV