Love seeing these boxes show up.5 Jul, 2016 in Head Hoggers tagged CP carrillo / haley horsepower / harley head porting / harley machining / Head Hoggers by headhoggers (updated 2339 days ago) Box full of CP Pistons. 107-18 Pistons. They have a 18cc dome on them. Pretty sweet. Contact us at Head Hoggers if your looking to step up that engine!