ORIGINAL: kansasjet
Dar Zeelon,
I am sure that you a correct about not all parts being interchangeable.
I was mostly talking about the two rossis I have, One side exhaust, one rear exhaust, and between them
the crank,rod,wrist pin and piston and sleeve will interchange.
Roger
[link=http://www.urbandictionary.com/define.php?term=roger+that]Roger that[/link], Roger. 
I guess you are right about these particular parts in the over-square .61 SE and RE engines.
But the newer 240R60E SE engine is different...
Your current engines' parts will not fit into it, nor would the current engine's part fit into your engines.
You should take that into account, when looking for the items that you need.