Anyone know if the 2.3 head will fit on the 2.0 without need for modification?

I would think that the combustion chambers would be bigger reducing the compression ratio quite a lot with the valves possibly hitting the narrower bore

Same bore and same heads.

The CR is the same IIRC and the difference in capacity comes from the 11mm taller block and stroke on the 2.3

To my knowledge the heads are identical, cam may be different though, other than that it should bolt straight on.