I had a 302 in my 87 F150 that had a small leak and it emptied most of the rad... The motor got so hot it didn't idle... I didn't notice this until I was on the freeway (gauge was faulty). Long story short I replace the coolant and small coolant line that had a pin hole leak in it. The engine was also down a quart of oil. Let everything cool and topped the oil and coolant and she fired right back up and I put many more miles on it. I hope your engine is okay too... Fingers crossed, it's no fun when something like this happens...