Don't sweat it. The Dyno Jet spring is longer and "springier" than stock and the kit comes with 2 different mains. 160 and 165 I think. The needle has a completely different profile as well. The instructions say that if you are using the stock exhaust then use the 160 and if you're using aftermarket use the 165. Again "I think", it's been awhile. If what I said is wrong someone will clear it up. As for question #5, there is no way you can emulate the kit or "Dave's Mods" no matter how you configure the stock carb. Do one or the other and you will have a much better motorcycle. Like I said the Dyno Jet kit came with the bike when I bought it so installing it was a no brainer but remember it's expensive. "Dave's mods" is basically a "free mod" and it will produce the same general results. What is "Daves mods"?