You obviously didnt check CAPS. There are P# differences for the MR longblock and the GSR longblock in the IX. IF you can tell me what differences are likely in the MR longblock vs the GSR/RS longblock that wouldnt require a different Part number I will believe you.

 

different part # on the long block could be a different harness, clip, or entirely different internals. without examining all the #s in the engine its impossible to say either way

 

Andenbre that is very true.

My point is that there sufficient differences to warrant a different part number, saying that they are identical is incorrect. The ACD lines are different (thats due to the 6 speed I realise) but the blocks are the same and the specs are the same (though materials may differ). This leaves internals as an obvious difference and since it held true with the VIII's that MR cams were different (same duration different centerlines) it would seem reasonable that it would hold true in the IX's as well.