1966 Mercruiser 120. Finally got it to fire up after 24 years of just sitting and then noticed a water leak under the Exhaust manifold. Took the Manifold off and noticed a hairline cracked block(Pictures Below). Is this repairable or am I just wasting my time on restoring this 1966 Starcraft? Is it worth buying another block? I was really wanting to restore this boat since it has been in the family for 45 years.