The casting # is 39000, there maybe a space between the 39 and 000. The stamp on the front of the block is hard to see but looks like 0F4224 the in larger print 1 5. The intake number is 3877757 which I ID'ed as a 64,64 327. I was told this engine came out of a 63 or 64 Corvette but can not find these numbers anywhere. Could it be a replacement motor? Thank you.