As a consultant for the OCATT (Orange County Auto Theft Task-force) I've seen many re-stamped cases approved by law enforcement.
I have never seen them approve a blank case. When presented with a blank case they (law enforcement) will assign a new number and attach a tag. If you have the old case and it matches the vehicle title they can ok the use of the original number.
I never suggested anyone by pass proper procedure. Nor did I ever suggest that I would do it for them.
But as usual, people make assumptions.

You're contradicting yourself here. So... they do approve blank cases and apply their asset tag making it not blank in the end. That would be one legal way to do it but would be undesirable for many collectors as it documents a tarnish on the pedigree of the vehicle.

There is a legal procedure for the department to approve restoration of a VIN or stamp which you had not mentioned to this point. Failure to mention this in your original response is what makes the original method suggested illegal and very dangerous without proper instruction as a method for forum members performing restorations. If Scott hadn't spoken up and the simple case stamp procedure by an independent had occurred then there could be some recourse if OP had his car cubed down by the gov't.

It's okay to be in the wrong and admit it once in awhile Henry. You can do it - I have faith.

Seriously, I'm the owner of the 911T in question and all I can say is I don't give a darn what number is on the block as long as I can drive my car. This thread is about figuring out how to fix a crack so the car can be driven not "lets see who knows more useless crap than the other guy." How about we sort out a way to fix the problem and take the arguments to an off topic thread.

Henry, thanks for the suggestions helping Rusty, hopefully the JB weld sorts the leak when we start it tomorrow. If not a new block may be in the works.

Stretch

Henry,
You discredit yourself and your well deserved reputation as an expert engine builder when you resort to such schoolyard bully tactics. Come on man. You are more of an adult than that.

Not only do you not know Scott and have zero knowledge of who he is, what his background is, or what he really knows or does not but calling him names doesn't make you right.

Make your argument on the merits of your argument, not the fact that you have built more engines than Scott will ever see.

I personally don't consider a restamped case a true numbers matching car. It is a car with a replacement engine that was an unnumbered case and restamped to match the original number. That is not an original engine. That is an original engine number on a replacement engine. Pretty cut and dry really. Not illegal and not decietful unless a seller tries to pass it off as an original engine instead of a correctly numbered replacement engine.