That is good to know..the CJ8 lawn mower plugs. Since I have some massaged 906 heads on my race 440 and header selection is still an open question that could be useful. Of course, I could simply run a set of individual pipes straight up and out through the hood and avoid the whole issue of clearance and burning my fingers while changing plugs. And it could be very entertaining when racing at night and I would be the only one on my block like that. But first I have to test the idea...