There may have been minor revisions depending on when the blocks were cast. Have you checked the part numbers?

Ford don't even list a 'Cosworth' block unless it's a 4x4 version. The T88 block has had the same part number from 1970 to Feb 1985 when it was revised and was given the 205 designation. Prior to this the 2.0 engines had 20 cast into the side of the block.
Until the 4x4 was introduced there was no 'Cosworth' block when referring to the YB engine.

HTH