Another Sparkplug Thread- plug reach

[California L33]

I've read a couple threads here about sparkplugs in W motor cars. They refer to using R44 and C44 plugs. Aren't these both short reach (standard) plugs? The '61 shop manual, and the plug finder at Sparkplug.com, says W motors need long reach plugs- like the 64, R64, etc. What are the advantages/disadvantages of using the shorter reach plug?

 

[Bungy]

The short reach plugs are only for the early 58 head that didn't have the watercooled plug bosses. All others use the long reach like XL or XLS. Originals were 43N or 44N. I don't know of any advantage in using a short reach plug.
You want the plug tip to be right in the combustion chamber so the flame travel is not hindered like it would be if the plug was "up in the hole"