i just picked up a 440 project for the winter. It is a 440 hull, but it turned out to have a heavily modded 550 system. Here are the parts that came on it, westcoast exhaust, factory pipe water box, westcoast ride plate, skat trak impeller, aftermarket (not tagged) aluminum high flow cylinders, milled head, aftermarket carb (not tagged). Unfortunately, in some way, a piece of piston managed to break off, and get recycled through the engine, while in the process bending the crank and breaking the magneto off the front of the block. I just bought another 550 for parts, i will use the lower end off that engine, and get the aluminum cylinders bored over 2 mm with a wiesco forged piston kit. I've read that with modded 550's its recommended to get a different crank, either a 440 crank or an aftermarket crank, would that be worth it, and furthermore, would it be worth just rebuilding the lower end just because. Are there any other weak points that would be worth fixing while its still apart. What would the estimated top speed of this ski be once complete. how much would this be worth once its complete. I will have pics soon.