a rattling noise whenever you put your foot on the gas and a load of steam - the first thing i would be looking at would be the water pump, chances are the bearings could have gone (that would be the rattling) and the steam could be a build up of pressure where the water flow couldnt go through the pump escaping through a weakness in a hose (weak jubiley clip or perished hose), the water may have sprayed from a pipe onto the alternator and made the steam (they get red hot lol), ive had that before on my rs and there was plenty of steam!!
did you lose any water?
i very much doubt the head gasket was the primary cause, but that said if the engine was starved of water the gasket may have failed, check your oil filler cap and header tank filler cap and check for mayo
