Leave it to Mopar guys to think weight and performance. As I was restoring my 1970 Challenger, I went to a swap meet looking for original cast iron 440 exhaust manifolds. I found a guy with a huge Igloo cooler full of Mopar cast iron. I offered to buy the exhaust manifolds and he said just take the whole thing...he meant the whole cooler full of cast iron, "Everybody wants to swap out the iron for aluminum intakes and such."