An IVA question...

[Longnose]

Just supposing you had a kit car which successfully went through the IVA process about 4 years ago and was all correctly registered with the DVLA. Then there was a serious engine failure which meant the engine was replaced with a unit of the same type and capacity.

Does that mean the IVA has to be done again or can the new engine number just be updated on the V5C?

I'm sure there will be opinions but I would like to know exactly what the regulations state or if anyone has personal experience of the same situation.

Thanks for any help.
-Longnose