Hi. New to the forum here. I work at a hardware store that offers rental lawn equipment, needless to say, it has its perks. I've managed to get a GX200, 240 & 270 for free off junk equipment. I'm in the process of building a go kart and finally decided to use the 270 rather than the cheaper 200. I do the porting myself on all my engines, so when I had the head off both 240 and 270, I was a little surprised. Why does the 240 have valve reliefs in the piston but the 270 doesn't? The only thing I can think of is the cam is different since the heads are the same and the stroke is the same. I couldn't find any real specs on the oem cams for either of these engines. If the cams are different, can I swap them? Thanks.