If you have an engine you really like , I would start looking & buying some spare parts for it before they become impossible to find. Stash them away , if you do ever sell the engine you can always sell the parts. I try to keep gaskets ,wrist pin , rod & a ring if it uses one. Very seldom have needed a piston & sleeve, cranks I have straightened. My old favorite yet is my OS 40 FSR, rebuilt it twice now. Engines are like women , they are all good ,some are just better than others !! MAX H.