Stiching a block is a no brainer, for the guys at a machine shop that is. I bought a boat a few years ago that had "milky" oil on the dipstick....tell tale sign of a water jacket crack. We pulled the motor tore it down, took it to the machine shop and for $100 they stiched it up and have been using it for 6 years now with no problem. If there is a crack in the block I would think there maybe one in the head as well. Have them stich it, you'll be happy, and you can hardly see it!
