Ok guys I am building a 421 serval with supporting mods such as inframe drag pipes and 35 pwk carbs advanced timing etc. so predicting 75 + hp as cast for now and later on once I have the entire bike as I want it I will probably do a serval style port which would bump up into the 85 + hp range. The bike will be used as a trail/play bike that will need to perform a little of all types of riding, hill climbs , buddy drags, and just about anything u can think to throw at it. My ? Is a +4 or +6 swingarm gonna be the better match. Will probably run 22 in tires and I'm a heavy rider so traction should not be an issue with either arm.