Our most popular build, and a great blend of durability, performance, and economy, Our BP660 starts with an aftermarket saw kit as the foundation, we then go over every piece and replace any that don't meet our stringent quality expectations with either OEM or quality aftermarket parts. We then carefully assemble the bottom end checking every tolerance along the way. The BP660 gets topped off with a Hyway titanikel 56mm piston and cylinder that we port for additional performance and longevity.