1989 iroc z28 with a 5.7 tpi and the temp is running about 240 what could the problem be and what could you do to fix it thanx?

I would start off trying a new thermostat. If it's never been replaced to your knowledge, then it's probably time for a new one since the car is 18 years old. Good luck and I hope that's all it is because it's an inexpensive fix.