Toyota Repair: ENGINE OVERHEATING, silicone sealer, head gasket

Question
I have a 1986 Toyota MR2, 5 speed NA with AC and 250,000 miles.
It has been eating alternator belts lately. On the way home it eat another one and before I could safely pull over and off the Interstate the enigine temp was 250 and it was really steaming. I got towed home and decided to replace the water pump and alternator as they had been on since I had 140,000 miles. I drained the oil from the oil pan and found no water mixed with the oil. When I pulled the cover off to look at the spark plugs I found a lot of coolant. Is it possible I wrapped the heads, blew a head gasket or did one of the expansion plugs  leak the coolant ? It doesn't look like an easy job pulling the heads so I am open to suggestions.
Thanks

Answer
Coolant in the spark plug holes doesn't indicate a blown headgasket, there aree three coolant core plugs you need to check and reaseal if needed, check verey closely for any cracks in the head near these core plugs, if there are none, remove the plugs and reseal them with a silicone sealer and see what happens, if the engine still overheats have a repair shop check for a blown headgasket.