Hi ,  Thanks for your reply.

Its sounds like I am guaranteed to have some stripped threads ?

Are the fasteners not going to break off rather than strip out ?   On other
vehicles, I have had to deal with that.

Is there a really really good brand of penetrating oil?

At the moment I am planning to just remove the front crossover pipe and
therefore dealing with only half the fasteners.

I may try Midas to see if they can weld up the crack and put it off a little
longer.

Cheers,    Steve