I will be fitting a new/different engine into the cabbie soon which has a different engine number to the original engine, obveiously

Now i'm going to register the new engine number onto the registration document with the DVLA.

Does this allow me to change the last 5 digits on the VIN plate from the old engine number to the new engine number?

Or does it have to stay the same?

I wanna get new ones made up, but wanna find this out first.