Does anyone know how close the various date codes should be on the major driveline parts (block, heads, manifolds, tranny, etc.) for an original engine and tranny combo? Are they usually within the same month or are they all over the place? Is there a reasonable number of days that should separate the casting numbers? Should one part such as the block have a date code before any other parts? It would seem to depend upon the inventory and production line procedures of GM but I have no clue as to what that might be and what to expect.
