+1 The important thing is to go through everything carefully. 38ac's engine build piece is fantastic. My older Metro 6/1 is pushing 3000 hrs this year. I had issues only because I didn't do the complete rebuild up front. I had sand filled grease under the piston crown, and a cylinder liner that projected too much and thus head gaskets failed regularly, and a crooked connecting rod. Those who just clean the sump and run them are the ones who may have some surprises, not likely with a serious build. It's just SO much easier to go over everything ONCE, before you put it in service, that I highly recommend that approach.