I had one of the first stroker engines that MM built back about 30 years ago. It was a welded factory crank with factory rods and Ross blower pistons. It didn't rotate when I got it since they machined it wrong. After they machined the parts correctly it ran, but it only lasted a few months before it seized a piston due to incorrect wall clearance. So that is my MM story. I know that they also built a bunch of good engines for customers but that was my experience.