might try abit of 2 part epoxy. we have had blocks come in where the fitters have used 2 part epoxy to fix up corrosion on the block deck.

still not as dum as the fitters out on site that tried to change the oil in a komatsu 6d170 with it running. got checked out and it ended up spinning 5 out of 6 big ends and cracked the crank. 70k worth of damage