All the searching i have done turned up nothing like this, its off my 351W i just got.. here is a pic and the number

1J107072, i didn't find any other numbers on the block, this is located on the drivers side above the transmission

 

it probably a partial vin to try decrease theft like etched glass etc

 

Hmm, so is there no way to find out what year this engine is from ?

 

yes there should be a casting number on the side of the block up by where the starter is on the ridge of the block

 

Are you sure the first digit is a 1, it looks like it could be a Z.

 

Another stamped number on a block is the build date. It is usually a shorter number, about 3 digits and a letter, like 6F14.
I would guess it is probably a vin because of the last 6 digits and the J.
One clue might be the J. What cars had a J to represent a 351?
Combine that with the casting number and the casting date on the block and you can get a guess what car or truck the motor is from and what year.

 

The only J code engines I've found are a 1968 302 4V and a 1971 429 CJ with Ram Air. Are you sure the engine is a 351 and not a 302?