My bike is a 2020 CDH with the factory TS116". I'm very confused and need some help. In stage 1 you upgrade AC and mufflers and need a tune because of the extra air flow. The Indian stage 2 kit includes 60mm throttle body, cams and injectors. My questions are: 1. I'm being told I can do the lloydz 585 cams and I don't need the TB, injectors and stage 1 exhaust. Just install the cams and tune, I already have a high flow AC. Why does Indian say you need all the extra parts? 2. I was looking at the Reinhart slimline duals header and mufflers. They also say no tune needed. How can you install a higher flowing exhaust and not tune?