I just finished reading through the "what engine is in your yanmar" and it seems that there are a lot of different engines that were used. I have been looking for an engine for my YM226d, engine #3T75HA, and I was wondering if there is any kind of cross reference between all the engines yanmar made that would show which ones are compatible replacements or direct replacements from model # to model #, ie would a 3T72HA or 3T84HA be an exact replacement for the 3T75HA since maybe only the bore is different?