Easy way out is NC30 fork bottom and mudguard.

Your standard NSR legs and damper rods will fit and this will allow you to use the larger disk.

The only problem is that the 276 disk uses a different caliper to the 297. The included angle of the caliper differs to allow for the greater disk dia. If the caliper isn't changed the disk rubs on the caliper body.

You could use NC30 calipers though that look the same as NSR but with the different included angle.
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If I have to take the carbs off once more...