There is no such thing as making a car "Numbers Matching." Unless you have all the documentation and the original engine/trans/rear end, you're commiting fraud, even if it's on yourself.

You can't stamp the VIN on a black that didn't have it, because the motor unit number (see Salmon's post) won't be right. If you mill the face of the block to re-stamp the engine unit number as well, then you might just as well stamp the block with some Ram Air code and sell it on eBay to some unsuspecting fool.