Let's put it this way. With a stock head and stock length valve, and Harland Sharp rockers, you would have to have over .900" lift to get the correct action at the valve. You can't get that with a stock length valve, and a longer valve would mean you would need more lift, and a longer valve, and more lift, and........... You can't get there!

I don't have a fast track into the mind of the cylinder head engineers, but my theory is, 'The consumer doesn't want to buy something that requires additional work, so we put stands on the head that will accept shaft style rockers. However, it can't be at the right place for everyone, so we will put it at the factory location. That way, if anyone complains, we can say we used the factory engineering'. That's my best guess.