Plenty on the Forum to see how other folks do it. New plugs are available, sacrificing the originals is a shame but If you need to be a bit brutal after pussyfooting with.....
Drilling the plugs, not the crank, to remove the factory punch locking pips....
Using a well fitting driver with a wide blade (slot type) or hex key.......and an impact driver set to undo!
Giving the driver a good smack with the lump hammer.....to shock the thread.
Applying heat with a blowtorch......to soften any locking compound, expand the metal, get even!!!!
Welding a nut onto the plug......
Still stuck? Best sharp drills at the ready, time to show who's boss, start by drilling a hole accurately into the plug centre, then increasing the hole diameter until you are left with just a defeated threaded cylinder which can be collapsed inwards leaving the original crank threads to receive new plugs.
I would have thought for initial professional assessment the size of the plug core was clear to anyone familiar with nuts, bolts and threads. Nor would I expect them to machine away the existing crank thread so no aftermarket plug would fit.
Swarfy.
