The JDM F22B was dohc. Pretty comparable to the H23. But since you can buy an H23 or a F22B for <750, it's just not worth it. Most of the performance gain was in the compression of the block. Save your change. Turbo your car, add NOS, cams, H22 it, or do something else. Even the H22-H23 hybrid is a pain in the ass from what I hear.