What short spark plugs?

[Pablo]

What stubby plugs do you guys use? Folks with very little clearance, what part numbers work?

 

[MB-Monkey]

champion 5843
i had one that worked just fine. It was all they had in stock but it works as good as the autolite 425

http://motorbicycling.com/f3/spark-plugs-5453.html?highlight=spark

also lists the others that work

 

[Pablo]

champion 5843
i had one that worked just fine. It was all they had in stock but it works as good as the autolite 425

http://motorbicycling.com/f3/spark-plugs-5453.html?highlight=spark

also lists the others that work

Thanks - the interesting thing is all the short plugs appear to have .375" or less reach, yet our heads really need 1/2". I guess not a huge problem, but not best performance.