What's the advantage of having an iron block? Mine is stamped 701 and it's iron. Previous owner said he installed a new crate engine. only put 10k miles on it. runs nice as hell but an iron block...

 

IMO, I don't like sleeved engines, give me an iron block.
I'm suspicious of "cold spots" in aluminum blocks, potential warpage?
Iron blocks more consistant in temp through out the block.
To me, the extra weight is a non-issue.