On sites like partzilla.com you can go into a certain year and model, blast your way down to an individual part, and it will tell you every other year and model that use the exact same part so you can know if they are direct swaps or not. Here it's showing the transmission main shaft is the same for all: 23211-HP5-601 MAINSHAFT (14T/17T) $123.81
Not sure exactly but from what I've been told, Honda changed a few part in there from the 07/ 08 models to the 09/ 11 models that supposedly gave the engine some performance changes. I was in a rush when the guy was explaining it to me so I was half paying attention and his description was vague at best so that's why I came here to the gurus to see if you all may have a more in-depth knowledge
There was a few running changes through production, I know the top ends changed a little bit and t he cranks part number changed at some point. But as far as interchangeability of the two motors as an assembly I think your fine.
Ok, so what needed to be taken out of my original 2011 engine and put into the 2007 engine that went in was the flywheel. Swapped them out, took it out to the deer lease and she purrs like a kitten. Now that I have a smooth running engine, I was able to hear what I think are bad bearings on the rear axle. Will be getting into that next week but I think (hope) that I'm on the tail end of all the repairs. Fingers crossed....
Lol... I can't take credit for that one. Neither can the guy who did the swap. A guy who's been a Honda specific mechanic for ages just happened to be at the shop when we were swapping the engines and noticed what was going on.