[Mark_C]

No. The drivetrain components were all built in parallel in different plants. Engine assembly had nothing to do with transmission assembly which had nothing to do with rear axle assembly.

Engines were usually assembled within a week or two before the car build date and are the components are usually cast a few days before assembly. Obviously the other engine components installed at the assembly plant, intake, heads etc. must be cast prior to the assembly date. Engine components added at the assembly plant, like carbs, distributor, exhaust manifolds may be dated before or after the engine assembly date as they are drawn from stock and installed at the vehicle assembly plant not the engine plant.

Rear axles are typically dated much closer to the car build date than any other drivetrain component, almost always less than a week from the vehicle build date, unless it is an odd gear ratio, or something like a JL8 rear disc axle which all seem to be dated around the same time.