the closest cast 1/15/68 to assembled 3/12/68 dates I have any info on are ~2-months, but most are much longer - that may be due to size of batches & rate at which they were used was it intentional??
the '66 & 1/68 blocks don't have the raised pad for the VIN stamp
I will check again, but I have a 1/15/68 block assembled 24May68 and it has the raised pad for a VIN but it is blank. Vin is in the normal spot for a 68 hemi motor.
was it intentional?? 
