If you look at the OS plug guide, the OS 8 was designed for .60 size engines and up. Of course, we all know that engines have their own temperment, and we will solve problems, sometimes, by going against recommendations. In this case, however, the OS 8 is the wrong plug. The A3, as mentioned by w8ye in the thread you started, is the way to go. My engine runs great on it, and it might be on its original plug, after 5 years,...not sure though. The OS 8 is definately the wrong heat range.

Andy