[Uncle Bob]

Just to stir it up some more, and perhaps in conflict with my buddy Fairlane's post, my understanding is that the NSN in the middle of the aluminum head is an indicator of the Weiand cheater head. But different from the one above is that it only says "Canada" rather than "Made in Canada", so maybe it's a combination of those two features. Here's a close up pic of the Weiand on my engine.....