Yes, that is just the date code of when the block was cast, so it will only be of limited use to I.D. it. To me it looks like maybe that date code has the two "dots" under the first number. Ford started placing two dots under the year digit ( the first digit ) starting in the second decade of FE block production, so around 1969 and later. Because of those two small dots it seems those later date codes often get messy during casting as a little sand can fall out of place. We can figure out if that is the case by knowing a little more about the block though. Does it have the 2 bolt or 4 bolt motor mount pattern? The 4 bolt pattern started in 1965 model year production, so if it has the 4 bolt pattern we would know it can't be 1963. Also, most earlier blocks had the date code on the side of the block, not under the oil filter adapter, so that is a clue. Does the block have the cast ribs on the side? We know the ribs started in the '70's, so that would be a clue. What is cast on the front of the block? We know the reverse "501" is a later feature for example. Do we know what vehicle this is in? ( we should since it's still in it lol ) and is it the original engine?, or is that something we're trying to figure out? I agree with Bruce that the last digits look like C27, and he's right, that's March 27th. If it is possibly the original engine, what is the scheduled or actual build date of the vehicle? What are the rest of the features of this engine - which intake manifold?, which exhaust manifolds? which exhaust bolt pattern? what carb? what distributor? Any reason to believe any of this has been changed? Do you see any other casting number on the outside of the block, either side - something like D3TE or D4TE ? It might not be possible to figure out exactly what it is from the outside, but we can maybe figure out some things.
