FV432 stuck plug help!

[Yohan]

Hi Gents,

I have an FV432 MkI with a stuck plug. I did not install these, so I don't know if it was cross-threaded or over-tourqued? I soaked it last summer in PB Blaster for hours and put a breaker bar on it with no kuck.

I have not hit it with an air impact wrench, but I'm afraid that's my only option. If I do this, what's the worse-case scenario? Does anyone out there know of a better way? Please help and thanks in advance!

John, NY