In case anyone is wondering, I was serious with my remark. Aluminum is much easier to work with than cats iron. I, for one, will buy every piece of reasonably priced aluminum (excuse me, aluminium) Canadian castings I can get my hands on.
As to weight savings, I've never seen any figures. Tomorrow, if I can get away with it, I'm gonna sneak the bathroom scale up to my shop and weigh a set of cast iron heads, an iron intake manifold, and corresponding timing cover and then do the same with the aluminum parts. Let's start a contest. I say the difference will be 85 lbs. What do you guys say? (If someone already knows, you can post it here and keep me out of domestic purgatory.) I'm talking 8BA stuff here.