bearing change - yes
When I had my Cessna 172 E2D overhauled last time I upgraded to 160hp.
I was told besides using different pistons/cylenders, that a bigger bearing would be placed in the front of the engine. I think that this entailed modifying the case and the crank.
The engine that is going into my RV9A started out as an E2D, but has been modified to 160hp and also to except the CS prop. This engine of course is no longer certified, but I was told that the modification resulted in an engine that could not be told from a D1A.
Kent