Theres not a lot of room for filters on a CB550. They make a 90 degree bend filter but, since it's all gravity fed, there will be a great chance there will be a low spot in your fuel line between the tank and carbs. I try and keep a constant downward slope for this stretch of fuel line. Maybe you could make use of 90 bend fuel fittings. Good luck. I believe all my fuel lines on the 550 are 1/4" not sure what the drain lines are, smaller for sure. You don't need fuel grade for these lines since gas isn't passing through them a lot or shouldn't be. Same with the camcover vent tube.