I have an 01 raptor 660 and i have a gytr carbonfiber slip on, proflow air filter kit, 7/8 inch holes drilled in my airbox (6) and lastly i have a 12 tooth front sprocket. And i dont know what jet to run and whats a good brand too.
There are alot of things to consider like elevation, temp, ect. The kit will come with instructions to help you out. The most popular is the dyno jet kit which is a good kit and comes in different stages.