ORIGINAL: Sport_Pilot
Just because the head will accept a long plug doesn't mean it has to have one. I assume the manual tells you what plug to use.
It has to have one in this case.
The T.H. engines come with "long" plugs installed.
It's what Tower, GMS and Supertigre supply with their engines too, out of the box.
The manuals specify the "superplugs" which are also longed nosed.