1982 glt

My son's 82 turbo sedan developed a serious oil leak yesterday. Today I discovered that the oil pressure sending unit was leaking- or rather the brass fitting it screws into. The leak was due to the brass fitting stress fracturing. The crack developed into a break trying to remove the brass fitting from the block. (I actually believe that the piece that eventually broke off in the block made about one half turn before seperating from the outer portion, but it doesn't want to move now) The remaining piece is flush with the outer surface of the block.

I have tried using an extractor to remove the piece with no success. I think it is self defeating as the tighter the extractor gets I assume the soft brass just expands to grip the cast iron block. Of course I have limited room to work in the space provided with the alternator removed.

Anyone have advice to offer? Do you think I should just try a little more torque on the extractor? The extractor is large enough that it is not bottoming out in the oil galley behind the fitting. Would heat work to my advantage? Heat and a shot of 134A directed at the center of the opening to contract the brass? Any ideas will be entertained. Thanks.

Randy