98 tacoma overheating not thermostat

My 98 sr5 3.4 got hot in a very short drive i noiticed my heater wasnt getting hot i assumed thermostat got home and seen that my radiator was cracked i know very little but i assumed got hot because t-stat wasnt opening so it built pressure and cracked but if that were the case shouldnt it go into overflow plus pulled t- stat boiled it opened fine so if not the t-stat and and still blew cold air heater core i dont know my buddy said fan clutch but seems like it shouldn't be that bad if t-stat is still working and fan clutch is bad also my water pump is fairly new and i didnt see any leaks what is the prob