Manifold stud removal

[Speedex750]

Long shot but maybe worth trying. 

https://youtu.be/KFdFsfSAuyc

Hi Alan,
Almost all the tricks are described above. I would suggest you don't dismiss heat so readily, a small propane torch will get a stud up to a cherry red colour. Once cooled re-apply a release oil and let it soak at least overnight. My 'go to' tool in these circumstances is a small pair of Stilsons, the stud is toast anyway. If it turns, don't be tempted to keep turning. Get more release oil in and give it time to get down the separated threads. I've just removed a full set of original studs getting twelve of the fourteen out. The others are right to say that redrilling isn't likely to recover the original thread, mine were close but a little too wobbley, I've used stepped studs. Don't forget to seal the threads on the new studs to stop water coming out.

I hope you get them out without too much bad language,

Dave