The Genesis aluminum blocks should be available soon. I believe the price is $4599. The iron Genesis blocks are $3299 but can be had for $2995 at Keith Craft Racing if there are any left at that price. There is no such thing as a pre-Arias Shelby aluminum block.
All the Shelby blocks were/are cast at Arias.
I like my turkey with mashed potatoes, gravy and cranberry sauce
HTH,
--Mike