If you decide to buy a 4mm, I just picked up a roller this weekend and got his project engine from him too. He bought a brand new +4 vitos crank, installed it, and then never finished it up. So the bottom end is complete, minus a clutch basket, been sitting for a couple months now. Then he ran out of cash, so he never finished the top end, stock cylinders 20 over, need another bore, and still needs the pistons to be purchased. Just thought I would give you a heads up if you were thinking about purchasing a crank, I have basicly a new one sitting here, I have the box for it too.