I don't want to get into saying that one builder is better than another. I have had good and bad luck with most all of them. When you talk to them make sure that you tell them what type racing that you are doing(XC, MX, or?) it make's a big difference is the way that the engine is done.People will talk about builder's just like you talk about which is a better truck; Ford, Chevy, Dodge, or ? It might take 2 or 3 times working on a cylinder to get it correct to your liking. Hope that this help's there are many good engine builders.