[TimG]

Many Corvette folks search for a virgin block, one that was sold over the counter with no stamping. These are perfect blocks to stamp although their availability is limited.
I've seen that the less of a certain engine installed in a car, the longer is the acceptable spread between the assembaly date and installation date. A friend is looking at a L89 automatic in a '69 Corvette, very few made. The spread is longer than typical as these were not used as quickly as a 427/390 horse motor. They tend to sit and wait in inventory.