Is the Headgasket ok matey
The damn fan belt snapped on mine when I had it, and this also turns the water pump. Only went in to the red for a few secs before I shut it off, and it did the gasket
Still, I think your prolly ok, mine ran like a bag of poo afterwards and misfired badly, but if yours is running OK now
Try leaving the water cap off, heaters on full, and check for any bubbles coming out of the header tank to get rid of the air lock