Ford Flathead Spark Plugs ?

I have a very high lift cam and use AC45 which has a shorter reach.

 

While rebuilding my '49 V8, I noticed that the original plugs didn't extend all the way to the end of the threads in the heads. With the plugs torqued down, there were still about a 1/4 inch of threads exposed...that can't be right.......can it?.

The measured depth of park plug holes in the head is 4/3", while the threads on the Motorcraft AL-9 plugs (Previous owner installed) were only 1/2".

I would think that having the electrodes up in the head, instead of being more exposed to the air/fuel mixture, would shroud the spark, preventing efficient ignition.

Has anyone ever noticed the same thing...if so, what did you do about it?

 

I've yet to fowl an NGK in my shitty old worn out flattie. It would eat champions for lunch.

 

Not bird fowl but regular foul..haha