[RodKnock]

Generally speaking, the new iron blocks will also have more meat so that they can bored larger than the aluminum blocks.

And some might say that the mating of the iron block/aluminum head combo might/could have some sort of chemical bonding issues.

Ultimately, for me in any case, it's all about the weight savings, which is roughly about 100-125 lbs on the front of the car.

Others will correct me if I'm wrong.