That block is VERY repairable. Drill and tap those corroded holes for a cast iron pipe plug, probably about a 3/8" or 1/2" NPT, screw plugs into the tapped holes with red LocTite, and grind and file them off flush. Then drill a coolant passage back into the plugged spots, using a head gasket as a drilling template.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!