383 - 906 Heads Question

[The Rebel]

So pulled my valve coves today to switch over to the OEM ones (My 68 Charger - A Work In Progress | Page 11 | For B Bodies Only Classic Mopar Forum).

While I know the part # is 2843906-6, does the -6 mean 6th mold?

Also looks like the cast dates are 12-29-67 and 01-02-68.

Drivers Side - Looks like cast date was 12-29-67


Passenger Side- Looks like cast date was 01-05-68

 

[4mulas]

Casting run. -1, -2, -3 etc.....

 

[The Rebel]

Thanks!