2g cam swap.

[Constant_Project21]

I recently sold my hks 264's to a friend of mine with a 2g (I own a 1g). When installing the intake cam, we notice that the cas has a spot to thread onto the cam, and the hks cam, does not have that threads to thread on there. Is there a different cas he has to use? I was under the impression that the cams were completely interchangeable.