I have an '85 17'Chris Craft Scorpion with a 120 HP Mercruiser motor.<br />Is the 120 and 140 block interchangeable?<br />Is it the same block bored and stroked?<br />Can I bore my 120 and use a 140 crank and, viola, a 140 motor?<br />Do they use the same head?<br />Assuming I will be removing the engine for a rebuild, what other upgrades can be done to my 120 for some extra ponies (cam, higher ratio rockers, head porting etc.)?<br />Thanks for any suggestions, ideas and input!<br />James