Engine parts are copied. The risk is not only that the part fails. It is that it fails in a way that takes the crank, the head, or the turbo with it.
Practical checks
- Ask whether the part is OEM or a named aftermarket brand
- Compare casting numbers and finish with a known sample
- Be wary of prices that sit far below every other quote for the same number
- Expect a supplier to ask for the engine serial
A serious seller will say when a part is aftermarket. They will not dress it up as something else. Keep the invoice and the part number. If a failure needs a claim, those two lines are what you will be asked for.
If a deal depends on secrecy about the brand, treat that as the answer and look elsewhere.