Hi Terry
Could you tell us why cutting the studs is the only choice? There are some options used on flathead V8s that just might work.
First is wood wedge method which I've used successfully too pop the heads on long stuck engine's. Key in this is cut the wedges to start with very fine angle from oak and use lots of them. Get them just started then very gentle taps round and round.
Example this at the very end of the process after switch to bigger wedges.
I should add that I had soaked the studs for a month in heat shop with ascitone and ATF.
Trick two was used on hotrod flathead with aluminum heads were the corrsion would seize to the studs. It used a thin hole saw that just fit over the stud. Have not seen one these in 50 years.
The problem of getting heads was even a problem when new that Ford change from studs to bolts very early in the production of the engine shown in the picture above. I have two of these engines built six months apart one has studs the later has bolts.
Hope this might help.
Cheers Phil