As mentioned, the instructions leave a lot to be desired. You'll receive minimal hardware instructions, so look at the assembly diagram (with a magnifying glass) to see which specific bolt and nut goes where. I started installing at 10:30 am and at 12:20 pm I was already testing. Including a short lunch break. It seems that the engine is easier to breathe and picks up speed faster. Tight pants. I am very satisfied and absolutely satisfied. Sounds great with my GT500KR exhaust!