I have an 1995 Seadoo GTX with a 657x engine with a bad lower rod bearing that beat up the crank, piston and head. I can get a used 720 engine at a good price from a friend that says it is interchangeable as long as I use my stator assy. Is this true? The only difference I can see is the routing of the the cooling hoses of the two on the head. Any info on this subject would be greatly appreciated.