<VV> Block Cracks

[Kevin Schrage]

I split the block halves of my 63 spyder the other day and noticed some cracks around the cam retainer in the block. I poked at them with my finger and got a chunk to come loose (mom always said picking at it would make it worse).  The cracks are only on the left block half, and extend about 1/2 inch on the bottom and 1/4 inch on the top of the retainer ring. I'm guessing the block is shot.  
Could I  just have the cracks machined out and have gaps on the top and bottom of retainer?
Should I buy a YR block or could I use any block to replace it? (A friend has what he says is a 110hp block that's from an old dune buggy project he'd sell for cheap)

Thanks
Kevin Schrage
63 Spyder