Stock M8 tune with no CAT in Head Hoggers tagged harley engine kits / harley head porting / harley machine shop / Harley Performance / Head Hoggers / M8 builds / mobile motorcycle tuning Just got this tune done on this 107″M8 bike. Bike is completely stock minus the cat. They gutted it themselfs. Not to bad! The blue is a run as is when they brought it.