426 hemi advice

I have a chance at a 66 426 hemi block for $1500( yes you read that right). My concern is, the block has had repairs made to an outer water jacket on both sides as well as a repair in main cap area. Seller said he bought it this way and doesn't know anything about the extent of the damage prior to repairs nor does he know who fixed it. Is buying this block as big of a gamble as I'm assuming it is? Are these repairs somewhat common and nothing to worry myself over? I'd love an elephant motor for my dart, but not if it's gonna fly apart the first time I stab the throttle