Alot of things go into jetting(elevation and temperature) are acouple, and they may require you to run bigger mains.
Not to mention mods and engine work.The reason they send them is because you may need to go that big at some point.
Stock mains are 200 ,some dealers will install anywhere from 190-220.
300's are fat,but I dont know your elevation or temp,I thought you meant 200's not 300's