Overheating an engine is always undesireable, but it doesn't necessarily finish it. Beings the radiator hose didn't burst, and immediately out of water is better. Kind of only you know how hot it was like if it wasn't pinging or knocking. If the rings didn't get hot enough to loose their flex on those cylinders, it could possibly eliminate the bottom end. Once you take the head off, and have it magna fluxed it will tell you if it is good or not, and if you are going to have to replace any other components in the head. Beings you had top end trouble before & all it could be like rolling the dice as to fixing the existing engine or replacing it with a good used one. Price wise and all it might just be a toss-up.