I've been looking for big bore kits for my 04yz450. I found an athena 480cc 98mm kit complete bolt on kit for 659$ I was wanting to know how many hp do I gain from this increase. Will it also have any disadvatages. I am thinking this is a better investment for an increase in hp vs. a 700$ pipe. I already have my suspension dead on and a rekluse so the next upgrade I was thinking is this kit. I have already had my ports cleaned up .If anyone knows of a better deal plz tell me where. The kit includes Athena nickel-carbide plated cylinder, Forged & Coated piston, Rings, Clips, Pin and gaskets.