Combustion chambers are smaller on 2 litre head and will raise the C.R


That being said a lot of the RS2000 boys get away with using the 2 litre head on 2.3 bottom end.


I skimmed a 2.3 head to raise the C.R when I did a 2.3 conversion many years ago and used RS2000 cams.


Make sure you use the 2.3 head gasket.