[Mcronk]

Good questions. Here is my thoughts based on the limited knowledge I have. First question about intake manifolds and block date codes. Of course the intake was the same used on most 4bbl applications in 68 and 69. So they were casting quite a few all the time. The early RAII blocks had the full 9792506 cast number on the block. Later block were "wiped and stamped" with the 2506. So my thinking is since the RAII was late in the production run, and no one knew how many orders they would get, after the early batch of blocks were used up they pulled the 9790071 blocks (2 bolt main but drilled for 4), machined them and installed 4 bolt caps, then wiped the 0071 and stamped 2506. I think it is quite possible that the intake would be closer to the build date of the car since they were using the intake inventory rapidly. As for your questions about replacement blocks not in the typical service replacement process I don't know. Could a person go to a dealer and order a block over the counter? If so would this block have a EUN (quality control/inventory purposes) a block code (per customer order) but no VIN stamp (since it was not installed on the assembly line and not a warranty replacement)? FYI my 67 400 HO has the original engine (EUN matches build card) the date codes for the block, heads, and intake are all the same month. The 67 was built in November of 66.