It's not really something I'm familiar with 9the Rover) but it's not untypical of a manufacturer to offer 2 outputs of basically the same engine, one might be for sport models or high-series models.
Sometimes the high-spec might be given away on the log-book, or a sticker on the engine. the hadnbook might give the game away too, but another thought is that between a H/C engine and a L/C one, the plugs would be different, so perhaps you can "reverse engineer" the answer ;)