[MattW]

The diffs are alloy - and as you correctly said spool up front.

I tried some black blades in the rear months ago, and they seemed fine. Although i know a few of the others haven't been quite so sure for the front, i haven't tried them in the front. I would just use your blacks ones and see how they go. If they are ok, then leave them!

We run grey belts all the time, even with 5 cell mod. They do wear a little more, and you can break the odd one with mod, but i would (and do) still run them).

As for spares, same as any other car really, usual suspects!