I addition to heating the block with a propane torch to evaporate the water, how about jacking up the entire side truck (since the engine is still in it), to tilt the water away from the crack in the block? I would think that one cinder block under each of the tires on the side where the crack would be enough gravity to keep the water away.

'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi