See my post re Bullet's Billet block.
the problem with a tall deck mega strong cast iron block would be the massive weight increse.
DART's 9.2" Deck "clevor" block is something like 30-40kgs heavier than a standard Cleveland block and around 20kgs heavier than Fords Nascar cleveland block and thats at standard deck height the 9.5" deck blocks are heavier again.
But if they did do a 91mm bore block I would run something silly like a 65mm stroke crank, super light rods and pistons and spin the bitch to 12,000+rpm using a large port billet 5 valve head.