Not necessarily. First, is this engine date of 5/14 the stamped "assembly" date on the engine pad? or is it the block "casting" date?
As for the car build date, 8/2 is either a VERY early 1970 model, or a VERY LATE 1969 model. Usually the plants would shut down for a couple of weeks in late July to early August for the model year changeover on the assembly lines. This car seems to fall right into that time period, so that could also have added to the differential between engine and car assembly dates.
More info, with photos would be helpful.