Prospective purchase engine ID help, please!

[Ngtflyr]

3999289 is a 454 as you stated, they were produced 1972 - 1975 for passenger, Chevelle, Corvette, and 73-75 for Monte Carlo's. The CE 103507 designates it as a warrenty replacement block. CE stands for Counter Exchange. I wouldn't think it would be a warrenty block for a 67 vette since the 289 blocks weren't produced until well after the vette's warrenty had expired. The motor should also have a casting date stamp on the rear topside of the eng the opposite side from the casting number. The 103507 is just the sequence number of CE engs as far as I have been told.