You never really said what you are trying to do other than freestyle/surf and want more power. I say sell your hull and engine. Use that money for an AM hull and a big bore. If you ride surf you don't needa big money billet engine, just a well tuned big bore and a properly setup hull. There's a lot more to a good running/handling ski than a big motor. There are many different ways to aproach this situation and you should try as many different setups as you can to really figure out what you want/need. You will hear a lot of opinions on what you "should" do but you need to realize it's not the billet that makes power, there's plenty of powerful packages that can be setup using a stock cylinder or other cast cylinders. Stock cylinders have their limitations on bore size and stroke that can be achieved and that's where the billet is necessary. I'm not saying billet is only good for huge engines, I've ridden a single carb XS735 billet engine that ripped... Just do your homework first. Surf riders and surf skis don't require the same powerplant as a flatwater freestyle competition ski