Just boring the stock cylinder for no reason is kinda pointless. It wont be enough of a power gain to notice. You could get it ported, it cost a lot less that 240 kits and is around the same performance gain. But a 240 has a lot more potential. So if money isnt a problem then go with the 240 kit, but if you can get an arisol kit from project blaster or a ct 240 kit. They are much better than vitos.