Question on engine block VIN

[wolf k]

Thanks for the replies, I am more interested in how you guys deal with the authorities when using used blocks when they ask for the VIN number of the car it came out of. I have just begun my licensing process and this was question the HP asked. So some have said they have a stamped number on the pad after the intake, my pad is blank.
After doing some more research, it sounds like if I provide a notarized receipt from shop I bought the block from, that will suffice.
Again, I just wanted to know what hoops you guys had to go through to license and register your used blocks.