I have a 1986 260 Mercruiser/5.7L that has about 4000 hours on it. Is it feasible for me to try and pull this engine and rebuild it myself? Or would I be better off just buying an already rebuilt engine from say, an on-line source that sells marine rebuilds? Cost is an issue for me, but so is mechanical ability/experience in doing this sort of thing. I know this sounds stupid, but, how hard would it be to rebuild this motor? I've done brake jobs, starter motors, fuel pumps, water pumps, etc., but I've never been inside an engine to speak of.