musashin

So I'm planning on buying this 260Z, thing is an amazing deal. The previous owner died in September, and the car is now being sold by his brother. He says his brother was adamant that the engine was from a 280Z. I thought it was interesting that the valve cover says Nissan and not Datsun... I really have no way of knowing, so I figured I'd ask the experts. So which engine is it?

This is what I'm talking about. The metal disk there circled in yellow.