Hey guys, having read every single post of this thread, along with watching every "Afleetcommand" video ever, decided to pull the trigger on one of these puzzles a month ago or so. Assembly was actually really straightforward. I was really surprised. Everyone panicking about the crank seals rolling when pressing the crank through actually got me a little nervous. But it was surprisingly simple to get the lip of the seal up over the step on the Clucth side of the Crank. Got the 660 finished up Monday. Along with Bridge Porting and Dropping the Cylinder, I decided to give the Velocity Stack/UNI Filter a try. Also figured out a way to run that filter set up, and still utilize the air box cover to keep crap out of the Carburetor area. Saw tested @ 175psi, and is capped at 12k until I run a few tanks through it. I'm extremely impressed. This saw is an already an animal, and it's still in "Limp Mode". Cant wait to see what it's fully capable of. As far as issues, the only ones I had were the typical chain tensioner gripes, and a useless chain brake link. Also the muffler didn't come with the gasket to seal the two halves...is that normal or something my kit lacked? Either way ill just grab one for a few bucks. Now im setting my sights on a 440 for the next project.