whats wrong

and now that i replaced the radiator, water pump and thermostat, my heat dont kick in. it blew hot before

someone pleasehelp me, i am spending alot of money on this car.

there are no check engine lights on. i can drive the car and it runs great. then with no warning at all she just cuts off. after about 15 or 20 minutes, you can start her back up, but will cut off again when at normal running temperature. No gages read hot. car just shuts off

When it "cuts off", squirt some starting fluid in the intake. If it fires, you know that it's a fuel related problem. If it doesn't fire, it means there is no spark. Stop throwing parts at it until you determine what is causing the problem.

if there is no spark--then what?

Check ignition coil for power out, if no power out check the wires going to the coil for power. (use an ohm meter) if power to the red wire, replace coil, if no power, check pick up coil in dist. & replace if faulty. You can look up proper way of testing online. good luck.