thats teh way to do it. Not cheap...but as close to being 100% reliable as you can get it.

part of the reason they take apart crate motors is to shave the heads to get more hp along with other tricks.. its nothing new...

that's what the top runners tend to do to stay competitive..

its a little sad that it has gotten to that point.. I kinda wish the rules were so that crate motors had to be used and they had a way to make sure no one took them apart to keep everyone honest but I'm nobody with no voice so it stays the way it is....