You know....as much as I hate to think it.....I am going to have to do some more research....according to my Perkins Shop Manual....the "contra rotating engine" is supposed to have an "X" in it.....and according to the full serial numbers I have...including build numbers....there is an "X" missing. Sooooo...
I'm wondering if my boat....a 79', with engines built in 77' has a transmission that reverses the shaft.
Well, back in the bilge I go!!
The vanes on the impeller for the fresh water pump are curved... But from what I can tell...the shaft and bearings are the same. The outer casing is a little different and apparently not interchangeable.... I know the "rebuild kit" for the contra rotating engine was discontinued...but the kit for the normal rotation engine is still available...so you would likely get all the parts for the contra rotating pump...except the impeller. The exploded view of the water pump in my manual doesn't indicate any difference...but the parts list does....so I am led to believe its because of the impeller.
I am not an expert, so before you take my word for it....I would talk to someone who is....