1972 Duster Build with my Daughter

Jim Kueneman said
There’s a high probability I’ll probably drill out the rest of the spot welds and switch the upper radiator support so it will look like the original 72 at first glance. I just left it connected for now to ensure the side radiator supports weee square and spaced properly. Get it all aligned in tact in the way it is then switch it

Thats really the best way to do that.

The vin sequence number stamping on the body started in 1969, along with sequence numbers on engine block and transmission side pan rail. All those numbers matching is great on a "numbers matching" restoration especially on high dollar muscle cars. It was originally done for anti theft purposes, or for police to help identify stolen cars or their main parts

On cars like yours the engine and trans numbers matching the body doesnt matter since it was not a desireable combination as originally built. State authorities dont care about that either because at this age the possibility the driveline has been swapped out is very high by now.

The body numbers however are pretty important that they match if at all possible. Sometimes when these vehicles were newer they might have had fender benders and needed core supports replaced. New ones were blank. Production body shops treating it as a collision repair would just toss the old one.

In your case if ever selling the car, somebody looking at the core support numbers and seeing them different than the vin on the dash would prob throw up the red flag even if you could show the swapped support, after it goes thru a few owners that bit of info gets lost.