I would think you could stand a .025-.030" cut in the back without pushing the trannie snout or TC snout too far into the crank. All doable.... but finding a machinist who can set it up right will be the trick; I don't imagine that is a typical setup for engine work.
if you have a lot of money in the block, it might be worth investigating. There are probably some garage machinists out there who would do it for $100, maybe $150.