Thread: TD5 Exhaust manifold studs

Just wondering if someone can tell me the diameter and thread of the Exhaust manifold studs? My front stud is MIA. It hasn't busted off as I can run an undersize bolt into the hole. I was hoping to put a bolt into it in the short term to try to quieten it down until I can afford to get the whole manifold done. Also if I am going to do this what would be the best type of bolt to use IE Stainless, High Tensile Etc?

M8 bolt or all-thread and nut will do for now.