Exhaust Manifold to Engine block Gasket -Replace or reuse.

[Ian_W]

Have recently ported my wastegate to 22mm and have reused the exhaust manifold to engine block gasket. Seems to be blowing now though. Is this a reusable item as per the metal gaskets or do you need to buy a replacement.
Also have been trying to find the torque value for the manifold nuts, and the wiki suggests a certain order to tighten the eight nuts.

Thanks in advance for any help.

Cheers

Ian W