So....What is YOUR opinion on VIN swaps ?

I don't know depends on why I guess.
Saying your restoring a very rusty 340 duster and buy a solid /6 car. So you cut the front half and rear half out of the donor car and floor and roof and install on the 340 car didn't you in around about and very difficult way swap Vins ?

In my opinion, no.

First, you're not trying to pass the vehicle off as a different vehicle. You're simply taking the sheet metal from one car to the next.

Second, while you are taking the metal from a donor vehicle, this happens all the time at body shops and is perfectly legal. Why? because you're not taking the vin from the donor car and trying to put it on the project car or vise versa. You're simply taking parts from one vehicle to another while those vehicles retain their original vins.

Third, if you do this correctly, you can keep the vin sections. For example, my trunk gutter on my 74 is replaced with a solid section from a 70 dart, I simply cut out the 70 VIN from the trunk gutter and replaced it with the cut out section from my 74. Why? So that if my car is ever stolen, the VINs match. Sure, i could have left it and probably nobody would ever check it, but I didn't want a vin from a different car on my car. Im sure the same could be done with the front, i forget where that one is at though.

Now, if you were to cut the vin out of the 340 car and put on the slant 6 and try to pass that off as the same 340 car, that would be illegal, same if you'd take the slant 6 vin(for whatever reason) and put on the 340 chassis and try to pass it as the slant 6 can.

Hopefully that makes sense?