Engine date vs engine component dates?

[Jeff H]

Some recent posts have me wondering what engine components should be dated for the time frame before the engine was assembled vs what components could be after engine assembly but before the car's assembly. When an engine was assembled, what was actually installed on the motor as it was initially assembled? Heads & intake?

So would the following components need to be dated before the engine assembly date?
- distributor
- alternator
- fan
- exhaust manifolds
- carb
- spark plug wires
- pulleys

Is there a known assembly sequence that allows for dating certain components? I'll use my 1970 L78 as an example. My car is 01C of 1970 and the motor is T1030CKO of 69. So should the components on the engine all be dated before 10/30 or can I use components from Nov, Dec and Jan as long as they are prior to the car's build date? I've always thought everything should be dated prior to the engine's assembly date but if a motor sat in a corner for a while, would it be a fully dressed motor?