Spark plugs?

[Oggz]

Hey guys, was reading a thread from here recently and tonight I decided to pull a plug to see what I actually had and to see what depth the thread was on my head.

this was the thread I was reading http://fefcholden.org.au/forum/index.php/topic,17007.new.html and the article about spark plugs

Now I am a little confused. I pulled the plug out of no1 and it is a NGK BP5S, going by the above thread it should be a deeper plug. When I look into the hole for the plug tho, I see what looks like 5 clean threads and unused threads with carbon built up on them....

the motor I have has B300907 on the block, I think its an EK grey by that number? obviously not the original so I have no where the head came from.

Didnt really have time to take any real measurements or take pics, but can anyone clarify or have pics of what I should really be looking for? or even if I should be stressed about what in there?

Cheers