At this juncture, I'm leaning towards a stroked 427 aluminum block Clevor produced by Fontana Automotive. It basically has the best features of a Cleveland and Windor in one lightweight block. For example, it incorporates the Cleveland's 2.75 inch main bearings,
oil pump and wider
oil pan (for maximum crank-throw clearance), plus the Windor's superior oiling system, taller deck height (9.5") and greater cam to crank spacing. Basically, this block rocks! The only downside it that it's $3750 which is a little pricey!
Bluedog