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.
It really depends on the build date of the chassis. Earlier builds usually have more scattered dates with all components (starter/alt/waterpump/distributor etc.) The blocks/heads/intake/exh. were usually spaced 2-3, sometimes 4 weeks apart. 1967's were mid year start in January...Not uncommon to see a B coded block with A coded heads in a D coded chassis.
The later in the model year typically had more tighter dates. My 1967 December built 68 has dates for rear end, engine, heads, intake, trans...all cast within 7 days. L177 heads L157 intake L187 block..L157 rear end.
Rationale? They had surplus of parts from prior model year plus a huge run of parts built to start the line.
The BEST way to solve this? Find a true, low mileage survivor, same year, same driveline with documentation close to your build date. Document the dates and compare.
Alot depended on the shift working at Lordstown. I have read and heard about workers on certain shifts so concerned about keeping the dates close for all engine components wheras another shift was not so concerned.
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1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
