Boring A14? A14's are never boring.
As for the size of the cylinders, they will obviously go to the third oversize of 1.5mm, which makes ti 77.5mm. After that, it depends on piston availability, your willingness to sleve the block if necessary [if walls get a bit thin] & finally of course, how much material is left between the cylinders to support a head gasket.
If these blocks are anything like the 1200, you should be safe at 79mm.
Chris