u cant reuse them as the viton coverings come away when you split them down - -a word of warning tyhough (learn from others mistakes; ie me ) unless both the head and block are 100% flat and smooth and clean - it wont make a good seal and your 150 quid for the gasket and 25 for the bolts will have just been wasted

here is what happens when u take it apart again.. there should be no bare metal exposed