do i need an engine age proof letter if im using a full donor with V5?

thanks
chris

I believe they still need proof of engine age, the V5 does not prove whether the engine was the original for the car or how old it is.

That would be the case if you are trying for a non cat test, if you are going for a cat test then the donor log book is fine. It was for me at IVA on 3rd Oct

From the IVA application form
https://www.gov.uk/government/publications/iva-application-form-for-passenger-cars-iva-1c

Evidence of the date of manufacture of the engine will be required at the time of inspection to determine the emissions limits for the vehicle. The donor vehicle registration document (V5) may be acceptable evidence, where it indicates the engine to be the original engine fitted to the donor vehicle.

If its a ford engine then the burton catalogue / relevant page of the burton website is acceptable by most inspectors

If its a ford engine then the burton catalogue / relevant page of the burton website is acceptable by most inspectors