Engine Assy.

[Matheous]

What are you legally obliged to tell DVLA when two vehicle engines are made into one? eg. serial numbers etc.....?

[ChuckFickens]

it's the engine block which will have the engine number on it they are worried about, as long as it's still the original block and all other parts are standard for the engine no need to tell the DVLA., though If any of the other parts have been replaced with any parts that would increase the engine capacity you would need to tell them.

also if any parts have been replaced with non standard parts you should inform your insurance company.