[itslow]

For reference, the aluminum 348/409 blocks that are now available from the aftermarket are $5k+. That's also from a manufacturer (World Products / Bill Mitchell Products) that specializes in aluminum engine blocks and heads.

Granted that market would probably have a bit smaller audience at this current time, but original 348/409 blocks are much more scarce and expensive than their Flathead counterparts, which I think would make the demand similar (or perhaps even greater) for a brand new block. An aluminum Flathead block would have to be quite a bit cheaper to garner sales.