Quote:
It would seem logical that the 1976 model 100A would use the later design block, but the chances that one would be found in Australia, then converted to rear drive for use in a Datsun 1000 would seem to be pretty slim.

With the realisation that this is a taller block than the 'regular' A10's that were included in this group, it would seem most likely that someone has re-labeled this engine to simplify some of those irritating bereaurocratic issues that accompany engine swaps.