I pulled the head on my SOHC ZC last night (well, this morning) to replace the head gasket. One of my secondary objectives was to verify just what kind of pistons were in the SOHC ZC block. I've been doing research online, and nobody really seems to know- if they say they do, the information isn't from a primary source- it's always "oh this guy said he saw this" or "it has to be this way". Well, here it is. Click on the picture to enlarge. I made sure to shoot an angle so that you could see the "ZC" and the "PM6" together in one picture. Check out the rest of the pictures through the link if you want to see the crusty head. LINK The SOHC ZC uses the exact same pistons as the D16A6. It's actually the exact same engine, but it is rated at a higher power level than the 106hp D16A6. I have information that leads me to believe that the SOHC ZC cam is more aggressive than the D16A6 cam, but I haven't taken mine out to measure it. The SOHC ZC is usually accepted to have around 118-120hp, and I really don't think that a simple cam upgrade (especially from Honda) would have yielded a 10+hp increase. Maybe the ECU is different too, but I have no way to find that out... I'm not running the SOHC ZC ECU. Comments?