My 396 block has a cast date G 23 9, the stamp pad is 0728 and my body is 08D ~8/22. Less than a week from a cast block to built then almost four weeks until it was in the car. That was 69 though, not 67, and with only 2,018 L34s built in 69 for Camaros I'm sure the turnover was slower. I'm not sure how many of the L34 blocks were built for Nova and Chevelle though.