What is the condition of this engine in terms of how long before it may need an overhaul?
If its high miles (over 60-70k miles for these engines most of the time), add some stop leak in it to buy you some time until a rebuild is in order. I did that on well worn, but great running 216 which had a 5 inch crack in the water jacket by the petcock drain. It still had a bit of a weep, but did not leave a puddle. I drove it for 20,000 miles after that with no issues.
