The sleeve/piston sets are new, and I have them bought &amp; paid for. If I should have bought something different, that's my fault,but at this point I plan on using them. I want to build a strong motor with off the shelf parts and add a custom cam grind and a bunch of porting and port matching which I can do myself with some direction. I would think shaving the head would be some cheap HP, but I know it can be overdone, too. I think if I can make this thing breathe better, I should be able to get near 50 HP at the PTO. What do you think?