The only reason that they are called structural is the fact that the pan bolts to the transmission like the block does. This is for the production vehicles to help reduce noise, vibration and harshness (NVH). For doing a swap it would be nice but it is not necessary.

 

I dont agree. They have to provide some extra strenght also. Most likely on a stock motor it's overkill but I think a high HP build would need the addded strenght

 

You don't have to believe me but thats the reason. I work where I have access to the engineering and other resources. Remember, these are designed for production vehicles that people want to have as quiet as a church mouse but more powerful than the can handle and never break or leak. The molded pan is great, less chance of leakage, less noise, looks cool but it does not make the block stronger.

 

The block itself is already ALOT stronger than a Gen 1. Why would you need more strenth? And how is a thin cast AL pan going to add any strenth to the engine block?

Ron