depends if its cracked all the way thru the water jacket-- if the crack is just on the outside of the block -it can be welded with high nickel rod- and a lot of heat to warm the block---
you can buy new blocks -- they were sent to france during the 2nd world war-- they been in storage ever since--
to many guys are takeing running flat heads out and putting overhead mkotors into cars-- they just throw the flatheads away-- -
gary- id try for a later year block- one with the removebal distribitor-- that engine he has -has the beehive distribitor -- sits right behing the fan in the center of the block-- its almost impossibal to change the points--
Flathead Engine Sites -- Hotrodders.com