What do you think of this plug?

I always like NGK or ND plugs. Your plug to me looks like it may be a bit rich on the jetting on the top end judging by the ring being black. I use NGK bkr5e-11 plugs. They work great for me. You may need the 6's though.

If you use autolites, use the AR series. They will have 4 #'s after the AR.