I would go to an automotive machine shop. Tell them exactly where it is cracked some times they can sleeve an engine. Sometimes they can be welded it all depends on where the crack is and how wide.
Most junk yards will do a check on where an engine is located and a price.
Check on ebay for a used block
http://www.ebay.com In my opinion he would be better off buying a used truck a dodge with a cummings engine and standard transmission. Ford had a problem with the ground strap getting corroded and the block letting go.