Before you spend a lot of money, you need to find out EXACTLY why your engines are giving you "problems". 470's were designed as marine engines, and are pretty sturdy little units. You will find very few complaints of problems with the "short block" (crank, rods pistons etc). The vast majority of problems are head related, due to the mismatch of an iron head on a aluminum block. You MAY not have to do a complete rebuild. Head gasket sealing problems and coolant leakage into the back cylinders are common problems (even if never overheated). A compression test will tell you a lot about the health of your engine (bad head gasket, valves, rings etc). As an example mine was running lousy last spring, found low compression in #4, new head gasket and valve job $500, and she runs like a champ again. Good luck, Oh and welcome to the "470 Club"
