I think it's time for my quads 1st rebuild. Its a 2010X and I'm running a mixxer ported head with 08 dirtbike cam and the slhg mod. Also got the TB ported and have the big 3. Fci, mad, and yoshi. I'm on the fence about sending my head to mmad. I hear good things about there work but they dont answer the phone. If I do end up getting in touch with them do any of you guys have any suggestions/ experience with different setups. Such as bigger valves bore size and so on? All I do is trail ride and drag race but I welcome to much hp. Also do they do cylinder work as well? I'd love to go up to a 480 and I dont mind buying race gas if needed. Just want some dependable hp that will bust all of my buddies asses. Thanks for reading.