[Marvin]

I'm afraid that the two centre diffs are very diff-erent (oh the pun!).

The 9E uses a 'short' centre diff, like the mini truggies and a 40T spur, whilst the nitro version uses a full-size centre diff and something like a 46T spur?

I suppose you may be able to fit the 40T spur to the nitro diff, you'd need all the 9E's diff mounts due to the varied height. You'd also need to check hole spacing of both diff mounts, as the 9 nitro's holes may be further apart.