Flange is a pretty easy fix and the dipstick isn't too big a deal. There is also the coolant resivoir return line that runs across where the header might sit. Upon inspection of my engine the dipstick appears to enter the engine in the similiar location as the zx2. You'd probably need that dipstick tube and possibly the stick to make it work with the header. The tube on our Zetecs simply bends from the center of the manifold off to the right so it enters right about in the same area as a zx2.
