[terry lee]

Try to look pass the weight issue.
Most of us won't notice the difference in everyday driving.
I looked at the alum. block as an insurance policy. If for any reason a rod should find its way thru the side of the block or any other disaster for that matter, at least I can repair my alum. block. Not quite so with the old iron FE. Yes, iron can be repaired to a degree, but do you want to HAVE TO RELY on it? Now try to replace that 427 block down the road. They seem to be pretty scarce right now and most are questionable. Those that can be verified cost as much if not more than the alum counterpart. We know for a fact that alum can be repaired over and over. Should you score a piston wall with the alum block, simply pull out old sleeve and replace it with a new one. Let's not forget one other factor, the 427 iron FE block is near 40 year old technology. Times have changed and so have the ways of casting and machining to provide a better and more consistant product.
Having said all that, you can't beat the look of all alum under the hood, or the WOW factor when showing it off.
Just my $.02 worth.
TL