Im looking at buying a VL calais with an Injected 5L in it does it need to have an engineers certificate for the motor or do i just have to notify the RTA of an engine change???

ask rta. In vic technically you have to inform if changing from carby to efi. They class it as a change in induction, smae in turbo or super charger on non turbo/supercharged motor.

I think if the injection is the only difference dont worry at all ,or just inform of the change of engine number, you will need a blue slip for that.

If it originally didnt have a 5 litre engine, and 5 litres is greater than 15% larger than what it did have, you would theoretically need an engineers certificate.

The VL Calais came out with a 5 litre V8 option, Though you may need an Engineers cert for the change in induction as mentioned especially if its a newer engine say out of a VN or later. Check with the RTA technical inquiries line or ask a known Mechanic. Then if all good be sure you get a separate receipt or stat deck for the motor with engine numbers etc.