split manifold (cast exhaust alloy inlet) bolts

[trabant]

The end snapped off the exhaust manifold its the split type with s cast alloy inlet manifold needless to say all of the bolts holding the two parts together snapped off despite penetrating oil by the ton and heat being applied. Anyone know the size/thread of these and or where to get them please.

[bmcecosse]

Probably as well to just drill and retap the holes -and use whatever bolts fit the thread you use for the tapping.